Tax deductions play an important role in determining how much income you pay taxes on. Whether you are a homeowner, employee, self-employed individual, or taxpayer with significant medical expenses, understanding available deductions can help you make better financial decisions and potentially reduce your tax liability.
Itemized Deduction Calculator
Estimate your eligible itemized tax deductions and compare them with your standard deduction to determine which option may provide a greater tax benefit.
One of the most important decisions when preparing a federal income tax return in the United States is choosing between the standard deduction and itemized deductions. Both methods reduce your taxable income, but they work differently. The standard deduction provides a fixed amount based on your filing status, while itemized deductions allow you to add together certain eligible expenses you paid during the tax year.
Our Itemized Deduction Calculator makes this comparison easier. It helps you estimate your eligible itemized deductions by considering medical and dental expenses, state and local taxes, mortgage interest, charitable contributions, casualty losses, and other qualifying expenses.
After entering your financial information, the calculator estimates your total itemized deductions and compares that amount with your standard deduction. It also identifies which method provides the larger deduction and estimates your taxable income after applying the selected deduction.
Instead of manually adding different expense categories, you can use this calculator to organize your information and understand how individual deductions contribute to your overall tax situation.
This guide explains how the Itemized Deduction Calculator works, how to use it, which expenses may qualify, how the calculations are performed, and how to interpret your results.
What Is an Itemized Deduction?
An itemized deduction is an eligible expense that taxpayers can claim individually on their federal income tax returns to reduce their taxable income.
Rather than claiming one fixed standard deduction, taxpayers who itemize calculate the total of their qualifying expenses. These expenses are generally reported on Schedule A (Form 1040), subject to IRS requirements and applicable limitations.
Common categories of itemized deductions include:
- Qualified medical and dental expenses.
- State and local income or sales taxes.
- Real estate and personal property taxes.
- Qualified home mortgage interest.
- Eligible charitable contributions.
- Certain casualty and theft losses.
- Other deductions permitted under applicable tax rules.
For example, suppose you have $8,000 in eligible medical expenses, $12,000 in deductible state and local taxes, $9,000 in qualified mortgage interest, and $4,000 in eligible charitable donations.
Your total potential itemized deductions would be calculated by adding the allowable amounts from these categories. However, some expenses have thresholds, caps, or additional eligibility requirements, so the entire amount you spend may not be deductible.
The purpose of itemizing is to claim qualifying expenses individually when their combined allowable amount provides a larger deduction than the standard deduction.
What Is an Itemized Deduction Calculator?
An Itemized Deduction Calculator is a financial planning tool that estimates how much you may be able to deduct from your taxable income through eligible itemized expenses.
The calculator considers several important financial categories and applies selected calculation rules to estimate your deductions.
It also compares your estimated itemized deductions with the standard deduction amount you enter.
The calculator provides the following results:
- Medical deduction after applying the 7.5% AGI threshold.
- State and local taxes before the deduction limit.
- Allowed state and local tax deduction.
- Qualified mortgage interest.
- Cash charitable contributions.
- Noncash charitable contributions.
- Deductible casualty and theft losses.
- Other eligible itemized deductions.
- Total estimated itemized deductions.
- Standard deduction comparison.
- Recommended deduction method based on the entered amounts.
- Estimated taxable income after the selected deduction.
These results provide a convenient overview of your potential deductions and help you understand whether itemizing may be beneficial.
How to Use the Itemized Deduction Calculator
Using the calculator is straightforward. You only need to enter your annual income, standard deduction, and eligible expenses.
Follow these steps to calculate your estimated itemized deductions.
Step 1: Enter Your Adjusted Gross Income (AGI)
Start by entering your Adjusted Gross Income (AGI).
AGI is generally your gross income after subtracting eligible adjustments to income. It is an important figure because certain deductions, including medical expenses, are calculated using AGI.
For example, if your annual income is $100,000 and your eligible income adjustments total $5,000, your AGI may be $95,000.
Use the AGI shown on your tax records or your estimated AGI for the relevant tax year.
Step 2: Enter the Standard Deduction Amount
Next, enter the standard deduction applicable to your filing status and tax year.
The standard deduction varies depending on whether you file as:
- Single.
- Married Filing Jointly.
- Married Filing Separately.
- Head of Household.
- Qualifying Surviving Spouse.
Make sure you use the correct amount for your tax year. Do not automatically use the same standard deduction every year because federal tax rules and deduction amounts can change.
Step 3: Enter Medical and Dental Expenses
Enter your eligible unreimbursed medical and dental expenses.
These may include qualifying costs such as:
- Doctor and specialist visits.
- Hospital services.
- Dental treatment.
- Prescription medications.
- Certain medical equipment.
- Eligible diagnostic services.
- Qualifying medical transportation.
Only expenses permitted by IRS rules should be included. Amounts reimbursed by insurance or another source generally cannot be claimed as unreimbursed expenses.
The calculator automatically subtracts 7.5% of your AGI from your entered medical expenses.
Step 4: Enter State and Local Income or Sales Taxes
Enter the eligible state and local income taxes you paid during the tax year.
Depending on your circumstances, you may generally deduct qualifying state and local income taxes or eligible general sales taxes, but not both for the same deduction calculation.
Examples include:
- State income taxes.
- Local income taxes.
- Eligible general sales taxes.
Use the amount supported by your tax records.
Step 5: Enter Real Estate and Personal Property Taxes
If you own property, enter your eligible real estate taxes.
You may also include qualifying personal property taxes, such as certain taxes based on the value of a vehicle.
Examples include:
- Eligible residential property taxes.
- Qualifying land taxes.
- Certain vehicle property taxes.
Not every property-related payment qualifies. Homeowners association fees, mortgage principal, and many other property expenses are not deductible as itemized taxes.
Step 6: Enter the Applicable SALT Deduction Limit
SALT stands for State and Local Taxes.
The calculator combines your entered state and local income or sales taxes with your eligible property taxes. It then applies the SALT deduction limit you enter.
The calculator includes a default limit of $40,000, but this amount should not automatically be treated as correct for every taxpayer.
The applicable limit can depend on the tax year, filing status, income-based limitations, and current federal law.
Update this field before calculating your results.
Step 7: Enter Qualified Mortgage Interest
If you own a qualifying home and have a mortgage, enter the eligible mortgage interest paid during the year.
Mortgage interest may be deductible when the loan and property satisfy IRS requirements.
However, the deduction can depend on factors such as:
- When the mortgage originated.
- The outstanding mortgage balance.
- Whether the property qualifies as a residence.
- Whether the loan proceeds were used for qualifying purposes.
- Applicable mortgage debt limitations.
Enter the deductible interest amount rather than your total mortgage payments. Mortgage principal and escrow payments are not automatically deductible mortgage interest.
Step 8: Enter Charitable Contributions
The calculator provides separate fields for cash and noncash charitable contributions.
Cash contributions may include eligible donations made through:
- Cash payments.
- Checks.
- Credit cards.
- Qualifying electronic payments.
Noncash contributions may include eligible donations of:
- Clothing.
- Furniture.
- Household goods.
- Electronics.
- Other qualifying property.
Donations generally need to be made to eligible charitable organizations. Noncash contributions must satisfy applicable valuation and documentation requirements.
Do not include donations to individuals or organizations that do not qualify under IRS rules.
Step 9: Enter Casualty and Theft Losses
If you experienced qualifying casualty or theft losses, enter the deductible amount.
Depending on current federal tax rules, certain personal casualty losses may be deductible when they result from a federally declared disaster and meet other requirements.
The calculator asks you to enter the already calculated deductible amount rather than the total property damage.
This distinction is important because insurance reimbursements, applicable thresholds, and other limitations may reduce the deductible amount.
Step 10: Enter Other Eligible Itemized Deductions
Use this field for additional deductions permitted under the tax rules applicable to your situation and tax year.
Only include amounts that qualify as itemized deductions.
Avoid entering expenses already included in another category because doing so could result in double-counting.
Step 11: Click Calculate
After entering your information, click the Calculate button.
The calculator processes your figures and displays a detailed breakdown of your estimated deductions.
Step 12: Review Your Results
Review the results carefully, especially:
- Total itemized deductions.
- Standard deduction.
- Recommended deduction method.
- Additional deduction compared with the alternative.
- Estimated taxable income.
The comparison helps you understand whether itemizing or using the standard deduction provides a larger estimated deduction based on your entries.
If you want to start again, use the Reset button to clear the calculator and reload it.
Itemized Deduction Calculator Formula Explained
Understanding the calculation formula helps you see how your final deduction is determined.
The calculator uses several formulas to estimate allowable deductions from the amounts you enter.
1. Medical and Dental Deduction Formula
The IRS generally allows taxpayers to deduct qualified unreimbursed medical and dental expenses only to the extent that they exceed 7.5% of their AGI.
The formula is:
\[ \text{Medical Deduction} = \max(0,\text{Medical Expenses}-(AGI\times0.075)) \]
Example:
Suppose your AGI is $100,000 and your eligible medical expenses are $12,000.
First, calculate the 7.5% threshold:
\[ 100,000\times0.075=7,500 \]
Next, subtract the threshold from your medical expenses:
\[ 12,000-7,500=4,500 \]
Your estimated deductible medical expenses are $4,500.
If your eligible medical expenses are less than $7,500, the deductible amount under this calculation is zero.
2. State and Local Tax (SALT) Formula
The SALT deduction combines qualifying state and local income or sales taxes with eligible real estate and personal property taxes.
The calculator uses this formula:
\[ \text{SALT Before Limit} = \text{State and Local Taxes}+\text{Property Taxes} \]
The allowable amount is then calculated as:
\[ \text{Allowed SALT} = \min(\text{SALT Before Limit},\text{SALT Limit}) \]
Example:
Suppose you paid:
- State and local income taxes: $8,000.
- Eligible property taxes: $6,000.
- Applicable SALT limit entered: $40,000.
Your total SALT expenses are:
\[ 8,000+6,000=14,000 \]
Since $14,000 is below the entered $40,000 limit, the calculator allows $14,000.
If your combined taxes were $45,000, the calculator would limit the deduction to $40,000.
Important: This is a simplified calculation. Actual SALT eligibility and limitations can involve additional federal rules, including income-based phaseouts and other restrictions.
3. Mortgage Interest Formula
The calculator uses the qualified mortgage interest amount you enter directly.
\[ \text{Mortgage Interest Deduction} = \text{Eligible Mortgage Interest} \]
For example, if your eligible mortgage interest is $9,500, the calculator adds $9,500 to your itemized deductions.
The calculator does not independently determine whether your mortgage satisfies IRS requirements. You must enter the eligible deductible amount.
4. Charitable Contributions Formula
Cash and noncash contributions are added separately.
The calculation is:
\[ \text{Charitable Contributions} = \text{Cash Donations}+\text{Noncash Donations} \]
For example:
- Cash donations: $2,500.
- Noncash donations: $1,000.
Total charitable contributions:
\[ 2,500+1,000=3,500 \]
The calculator adds $3,500 to your estimated itemized deductions.
Actual charitable deductions may be subject to percentage-of-AGI limits, substantiation rules, valuation requirements, and other restrictions that this calculator does not independently apply.
5. Total Itemized Deduction Formula
After calculating the medical and SALT deductions, the calculator combines all entered eligible categories.
The formula is:
\[ \begin{aligned} \text{Total Itemized Deductions}={}& \text{Medical Deduction}\\ &+\text{Allowed SALT}\\ &+\text{Mortgage Interest}\\ &+\text{Cash Contributions}\\ &+\text{Noncash Contributions}\\ &+\text{Casualty Losses}\\ &+\text{Other Deductions} \end{aligned} \]
This gives you the estimated total itemized deduction.
6. Standard Deduction Comparison Formula
The calculator compares your itemized deductions with your entered standard deduction.
The formula is:
\[ \text{Selected Deduction} = \max(\text{Itemized Deductions},\text{Standard Deduction}) \]
There are three possible outcomes:
- If itemized deductions are higher, the calculator identifies itemizing as the larger deduction.
- If the standard deduction is higher, it identifies the standard deduction as the larger option.
- If both amounts are equal, either method provides the same estimated deduction.
7. Additional Deduction Difference Formula
The calculator also shows the difference between the two deduction methods.
\[ \text{Difference} = |\text{Itemized Deductions}-\text{Standard Deduction}| \]
For example, if your itemized deductions are $30,000 and your standard deduction is $25,000, the difference is $5,000.
This means itemizing provides $5,000 more in deductions than the standard deduction, based on the entered figures.
8. Estimated Taxable Income Formula
Finally, the calculator estimates your taxable income after applying the larger deduction.
\[ \text{Taxable Income} = \max(0,AGI-\text{Selected Deduction}) \]
For example, if your AGI is $100,000 and your selected deduction is $30,000:
\[ 100,000-30,000=70,000 \]
Your estimated taxable income is $70,000.
This is a simplified estimate. Other adjustments, deductions, income rules, and tax provisions may affect your actual taxable income.
Practical Examples of Using an Itemized Deduction Calculator
The following examples demonstrate how different financial situations can affect the decision between itemizing and taking the standard deduction.
Example 1: Homeowner With Mortgage Interest and Property Taxes
Consider a homeowner with the following annual financial information:
| Financial Category | Amount |
|---|---|
| Adjusted Gross Income | $110,000 |
| Standard Deduction (illustrative) | $30,000 |
| Medical Expenses | $15,000 |
| State and Local Taxes | $9,000 |
| Property Taxes | $5,000 |
| SALT Limit Entered | $40,000 |
| Mortgage Interest | $12,000 |
| Cash Donations | $3,000 |
| Noncash Donations | $1,000 |
| Other Deductions | $0 |
First, calculate the medical deduction.
\[ 15,000-(110,000\times0.075)=6,750 \]
Next, calculate the SALT deduction:
\[ 9,000+5,000=14,000 \]
The remaining eligible amounts are:
- Mortgage interest: $12,000.
- Cash contributions: $3,000.
- Noncash contributions: $1,000.
Total itemized deductions:
\[ 6,750+14,000+12,000+3,000+1,000 =36,750 \]
Itemized deduction is higher
The estimated comparison is:
| Deduction Method | Amount |
|---|---|
| Itemized Deductions | $36,750 |
| Standard Deduction | $30,000 |
| Additional Deduction | $6,750 |
Estimated taxable income:
\[ 110,000-36,750=73,250 \]
Based on these illustrative figures, itemizing provides a larger deduction.
Example 2: Taxpayer With Limited Deductible Expenses
Suppose another taxpayer has a relatively simple financial situation.
| Financial Category | Amount |
|---|---|
| Adjusted Gross Income | $75,000 |
| Standard Deduction (illustrative) | $23,000 |
| Medical Expenses | $3,000 |
| State and Local Taxes | $2,500 |
| Property Taxes | $1,500 |
| SALT Limit Entered | $40,000 |
| Mortgage Interest | $0 |
| Cash Donations | $1,000 |
| Noncash Donations | $500 |
| Other Deductions | $0 |
Calculate the medical threshold:
\[ 75,000\times0.075=5,625 \]
Since medical expenses are only $3,000, the deductible medical amount is zero.
The SALT deduction is:
\[ 2,500+1,500=4,000 \]
Total itemized deductions:
\[ 4,000+1,000+500=5,500 \]
Comparison:
| Deduction Method | Amount |
|---|---|
| Itemized Deductions | $5,500 |
| Standard Deduction | $23,000 |
| Difference | $17,500 |
Standard deduction is higher
The standard deduction provides a larger deduction in this example.
Estimated taxable income:
\[ 75,000-23,000=52,000 \]
This example demonstrates why itemizing is not automatically the best option for every taxpayer.
Itemized Deductions vs. Standard Deduction
Both deduction methods reduce taxable income, but they have different requirements and advantages.
| Feature | Itemized Deduction | Standard Deduction |
|---|---|---|
| Calculation | Add eligible expenses | Fixed amount |
| Medical expenses | Subject to applicable threshold | No separate medical calculation |
| Mortgage interest | May qualify | Included in fixed deduction |
| Charitable donations | Eligible donations may qualify | No separate deduction |
| SALT | Subject to applicable limits | Included in fixed deduction |
| Documentation | Detailed records generally required | Usually simpler |
| Best suited for | Taxpayers with substantial qualifying expenses | Taxpayers whose eligible expenses are lower |
The most important factor is the total allowable deduction rather than the total amount of money you spent during the year.
For many taxpayers, the standard deduction is simpler. However, homeowners, individuals with substantial eligible medical expenses, and taxpayers with significant qualifying charitable contributions may benefit from calculating their itemized deductions.
Which Expenses Can You Include in Itemized Deductions?
Knowing which expenses qualify is essential for getting a meaningful estimate.
Medical and Dental Expenses
Qualified medical expenses can include certain healthcare services, prescription medications, dental treatment, and eligible medical equipment.
However, the expenses must satisfy IRS requirements, and only the amount exceeding the applicable AGI threshold is generally deductible.
State and Local Taxes
State and local income taxes or qualifying sales taxes may be included, along with eligible real estate and personal property taxes.
The combined deduction is subject to applicable SALT limitations.
Mortgage Interest
Qualified mortgage interest may be deductible for eligible homeowners.
You should review your mortgage statements and relevant tax documents to determine the amount that qualifies.
Charitable Contributions
Eligible contributions to qualifying charitable organizations may be deductible.
Cash and noncash donations can have different documentation and valuation requirements.
Casualty and Theft Losses
Certain losses may qualify under federal tax rules, including specific disaster-related losses.
Ordinary personal property damage does not automatically qualify for an itemized deduction.
Other Eligible Deductions
Some taxpayers may qualify for additional itemized deductions depending on their circumstances and the tax year.
Check the applicable IRS Schedule A instructions before including any additional expenses.
Benefits of Using an Itemized Deduction Calculator
An itemized deduction calculator offers several advantages when organizing your annual tax information.
1. Saves Time
Manually calculating different expense categories can take time. The calculator combines your entered amounts and performs the basic calculations automatically.
2. Helps Compare Deduction Methods
One of its biggest benefits is the ability to compare itemized deductions with the standard deduction.
You can quickly identify which method produces a larger deduction based on your information.
3. Calculates Medical Expense Thresholds
Medical expenses are subject to a 7.5% AGI threshold for most taxpayers claiming the medical expense deduction. The calculator automatically applies this threshold.
4. Accounts for the SALT Limit You Enter
The tool combines qualifying state and local taxes with property taxes and applies the deduction limit entered in the calculator.
5. Provides a Detailed Breakdown
Instead of showing only one final number, the calculator displays individual deduction categories. This makes it easier to identify which expenses contribute most to your total.
6. Helps With Tax Planning
You can use estimated figures to understand how different expenses may affect your deductions and plan for future tax years.
7. Estimates Taxable Income
The calculator also estimates your taxable income after subtracting the larger of the two entered deduction amounts from AGI.
Tips to Maximize Your Eligible Itemized Deductions
If you are considering itemizing, the following tips can help you organize your finances and avoid common mistakes.
1. Keep accurate financial records. Save receipts, medical bills, mortgage statements, charitable donation acknowledgments, and property tax records.
2. Review your medical expenses. Make sure you include eligible unreimbursed expenses and exclude amounts reimbursed by insurance.
3. Check your SALT limitation. Federal SALT rules can change. Always use the applicable limit and account for any income-based restrictions.
4. Maintain charitable donation records. Keep bank records, receipts, written acknowledgments, and appropriate valuation information for noncash contributions.
5. Review your mortgage interest statement. Form 1098 can help you identify mortgage interest reported by your lender.
6. Avoid double-counting expenses. An expense should not be included in multiple deduction categories.
7. Compare both methods every year. Your financial circumstances can change, so a deduction method that worked last year may not provide the largest deduction this year.
8. Use the correct tax year. Standard deductions, deduction limits, and eligibility requirements can change between tax years.
9. Understand the difference between deductions and tax credits. A deduction generally reduces taxable income, while a tax credit directly reduces qualifying tax liability.
10. Consult a qualified tax professional when necessary. Complicated mortgage arrangements, disaster losses, large charitable donations, and income-based limitations may require professional guidance.
Important Limitations of This Itemized Deduction Calculator
Although this calculator provides a helpful estimate, it does not perform a complete federal tax return calculation.
There are several important limitations to understand:
- It applies the 7.5% AGI threshold to entered medical expenses.
- It applies the SALT cap as a simple maximum based on the amount entered.
- It does not independently verify mortgage interest eligibility or mortgage debt limits.
- It does not apply all charitable contribution percentage limitations.
- It does not independently verify whether charitable organizations qualify.
- It does not calculate all casualty and theft loss restrictions.
- It does not determine eligibility for every possible additional itemized deduction.
- It does not account for every tax adjustment, credit, exemption, or special tax provision.
The calculator also does not estimate your final federal tax bill. Its taxable income result is a simplified estimate based on AGI and the selected deduction.
For accurate tax preparation, review the latest IRS instructions for Form 1040 and Schedule A and use the rules applicable to your filing status and tax year.
Frequently Asked Questions (FAQs)
1. What is an Itemized Deduction Calculator?
An Itemized Deduction Calculator is an online financial tool that estimates eligible itemized tax deductions. It adds qualifying expenses, applies selected limitations, and compares the total with the standard deduction to help identify which method provides a larger deduction.
2. How do I calculate itemized deductions?
Add your allowable medical and dental expenses after the applicable AGI threshold, deductible state and local taxes, qualified mortgage interest, charitable contributions, eligible casualty losses, and other permitted deductions. The total represents your estimated itemized deductions.
3. What is the 7.5% AGI rule for medical expenses?
The IRS generally allows taxpayers to deduct qualified unreimbursed medical and dental expenses only to the extent they exceed 7.5% of adjusted gross income. For example, if your AGI is $100,000, the first $7,500 of eligible expenses does not qualify for this deduction.
4. What does AGI mean in an itemized deduction calculation?
AGI stands for Adjusted Gross Income. It is generally your gross income after eligible adjustments to income. It is used to calculate certain tax deductions and determine eligibility for various tax benefits.
5. Is itemizing better than taking the standard deduction?
Itemizing is generally beneficial when your total allowable itemized deductions exceed your standard deduction. If your itemized deductions are lower, the standard deduction generally provides a larger deduction. You should also consider applicable eligibility and filing rules.
6. Can I deduct mortgage interest?
Qualified mortgage interest may be deductible if your mortgage and property meet IRS requirements. The deduction can depend on mortgage dates, loan balances, property use, and other restrictions. Mortgage principal payments are not deductible as mortgage interest.
7. What does SALT mean in itemized deductions?
SALT stands for State and Local Taxes. It generally includes qualifying state and local income or sales taxes, real estate taxes, and eligible personal property taxes. The combined deduction is subject to federal limitations.
8. Can I deduct property taxes on my home?
Eligible real estate property taxes may be included in itemized deductions. However, the deduction is subject to applicable SALT limitations. Homeowners association fees and ordinary property maintenance expenses generally do not qualify as deductible property taxes.
9. Are charitable donations tax deductible?
Qualifying charitable donations may be deductible when made to eligible organizations and when applicable IRS requirements are satisfied. Cash and noncash donations may have different documentation, valuation, and deduction limitations.
10. What is the difference between cash and noncash charitable contributions?
Cash contributions involve monetary donations, such as checks, credit card payments, or qualifying electronic transfers. Noncash contributions involve donating property, such as clothing, furniture, and household items. Noncash donations generally require appropriate valuation and supporting records.
11. Can I deduct medical expenses paid for my family?
Certain qualified medical expenses paid for yourself, your spouse, or qualifying dependents may be deductible if the applicable IRS requirements are met. The expenses must generally be unreimbursed and exceed the applicable AGI threshold.
12. What happens if my itemized deductions equal my standard deduction?
If both deduction amounts are equal, they provide the same estimated deduction. The calculator identifies this situation as an equal result. You can then consider the applicable filing requirements and practical documentation involved in each method.
13. What happens if my itemized deductions are lower than my standard deduction?
If your allowable itemized deductions are lower than the standard deduction, taking the standard deduction generally provides a larger reduction in taxable income. The calculator identifies the standard deduction as the higher option.
14. Does an itemized deduction reduce my tax bill directly?
An itemized deduction generally reduces taxable income rather than directly reducing your tax bill. The actual tax savings depend on your taxable income, applicable tax rates, filing status, and other tax provisions.
15. Is the Itemized Deduction Calculator accurate for every tax year?
The calculator provides an estimate based on the figures and limitations entered. Tax laws, standard deduction amounts, SALT limits, and eligibility requirements can change. Always update the inputs for the relevant tax year and verify your results against current IRS guidance.
Final Thoughts
Choosing between itemized deductions and the standard deduction is an important part of federal income tax planning. The right method depends on your income, eligible expenses, filing status, and the tax rules applicable to your situation.
Our Itemized Deduction Calculator simplifies this process by organizing common deduction categories, applying the medical expense threshold, limiting SALT deductions according to your entered cap, and comparing your estimated itemized deductions with the standard deduction.
Whether you are a homeowner paying mortgage interest, a taxpayer with significant medical expenses, or someone making charitable contributions, this tool can help you understand how your eligible expenses may affect your taxable income.