When comparing prescription stimulant medications, it can be difficult to understand how doses of different products relate to one another. Medications such as Adderall, dextroamphetamine, amphetamine, methylphenidate, Concerta, and Vyvanse contain different active ingredients or formulations, so their milligram amounts cannot automatically be treated as identical.
Stimulant Conversion Calculator
What Is a Stimulant Conversion Calculator?
A stimulant conversion calculator is an educational tool that estimates how the daily dose of one stimulant might compare with a standardized reference category.
The calculator in this tool includes six selectable medications:
- Adderall (Mixed Amphetamine Salts)
- Dextroamphetamine
- Amphetamine
- Methylphenidate (Ritalin)
- Concerta (Extended Release Methylphenidate)
- Vyvanse (Lisdexamfetamine)
The user then chooses between two comparison targets:
- Amphetamine Equivalent
- Methylphenidate Equivalent
The calculator first converts the selected medication into an estimated base amphetamine-equivalent dose. When the target is amphetamine, that intermediate value is displayed. When the target is methylphenidate, the calculator doubles the intermediate value.
The purpose is to give users a common mathematical reference point for educational comparisons.
However, this type of calculation should not be confused with a universally accepted clinical dose-equivalence standard. Published clinical guidance includes some product-specific conversion relationships, while also explicitly warning that many stimulant products should not simply be substituted on a mg-for-mg basis because of differences in pharmacokinetics and formulation.
Why Stimulant Dose Comparisons Can Be Complicated
At first glance, comparing stimulant doses might seem as simple as comparing the number of milligrams. It is not.
Different stimulant products can have differences in:
- Active ingredient
- Isomer composition
- Immediate-release or extended-release formulation
- Absorption characteristics
- Duration of action
- Timing of peak concentration
- Pharmacokinetic profile
- Individual response
- Tolerability and adverse effects
For example, immediate-release methylphenidate and extended-release methylphenidate may contain the same general active ingredient while producing very different concentration-time profiles.
Likewise, a product containing mixed amphetamine salts is not automatically interchangeable with a product containing lisdexamfetamine simply because both ultimately relate to amphetamine pharmacology.
Clinical literature specifically highlights formulation, onset, duration, intermediate- or long-acting components, and stimulant formulation as important considerations when making therapeutic substitutions.
A 2026 review of stimulant substitution strategies likewise emphasizes differences between amphetamine and methylphenidate, isomer composition, duration of action, dose equivalence, and patient-specific factors when changing treatment.
Stimulants Included in This Calculator
The calculator offers six medication choices. Here is an overview of what each represents.
| Medication | General Category | Included in Calculator |
|---|---|---|
| Adderall | Mixed amphetamine salts | Yes |
| Dextroamphetamine | Amphetamine stimulant | Yes |
| Amphetamine | Amphetamine stimulant | Yes |
| Methylphenidate (Ritalin) | Methylphenidate stimulant | Yes |
| Concerta | Extended-release methylphenidate | Yes |
| Vyvanse | Lisdexamfetamine | Yes |
Adderall
Adderall contains mixed amphetamine salts. The calculator assigns this medication an amphetamine-equivalent factor of 1.0.
That means the calculator treats the entered Adderall dose as the baseline for its internal amphetamine-equivalent calculation.
Dextroamphetamine
Dextroamphetamine is assigned a calculator factor of 1.2.
Under this tool's mathematical model, the entered dose is multiplied by 1.2 to produce its estimated amphetamine-equivalent value.
Amphetamine
The calculator uses 1.0 as the factor for amphetamine.
It therefore functions as another baseline reference in the calculation.
Methylphenidate
Methylphenidate is assigned a factor of 0.5 by the calculator.
This does not mean that every clinical methylphenidate-to-amphetamine conversion should use this exact factor. It is simply the mathematical relationship programmed into this educational tool.
Concerta
Concerta is an extended-release methylphenidate product. The calculator also applies a 0.5 factor to Concerta.
Clinical conversion decisions may require much more than a simple ingredient-based calculation because extended-release products have different pharmacokinetic profiles. Published guidance includes product-specific examples for converting immediate-release methylphenidate to Concerta, illustrating that formulation and dosing schedule matter.
Vyvanse
Vyvanse contains lisdexamfetamine, which is a prodrug of dextroamphetamine. The calculator assigns it a factor of 0.3.
This factor is part of the calculator's educational model and should not be treated as a universal clinical conversion rule.
How to Use the Stimulant Conversion Calculator
Using the calculator is straightforward.
Step 1: Select the Current Stimulant
Choose the medication that corresponds to the daily dose you want to compare.
For example, you might select:
Adderall (Mixed Amphetamine Salts)
Step 2: Enter the Current Daily Dose
Enter the daily dose in mg/day.
For example:
20 mg/day
The calculator accepts decimal values as well as whole numbers.
Step 3: Select the Conversion Target
Choose either:
Amphetamine Equivalent
or
Methylphenidate Equivalent
The selected target determines how the calculator handles the intermediate amphetamine-equivalent value.
Step 4: Click Calculate
Select the Calculate button.
The calculator will display:
- Converted Equivalent Dose
- Original Medication
- Conversion Target
Step 5: Review the Result Carefully
The number shown is an approximate educational comparison generated from the calculator's predefined conversion factors.
It should not be interpreted as an instruction to take that amount of another medication.
Stimulant Conversion Formula Used by the Calculator
The calculator uses a two-stage mathematical process.
Step 1: Calculate the Amphetamine-Equivalent Dose
The first formula is:
Amphetamine-Equivalent Dose = Current Daily Dose × Conversion Factor
The conversion factor depends on the stimulant selected.
According to the calculator's programmed values:
| Stimulant | Calculator Factor |
|---|---|
| Adderall | 1.0 |
| Dextroamphetamine | 1.2 |
| Amphetamine | 1.0 |
| Methylphenidate | 0.5 |
| Concerta | 0.5 |
| Vyvanse | 0.3 |
Step 2: Convert to the Selected Target
If the target is Amphetamine Equivalent, the calculator uses the amphetamine-equivalent dose directly:
Amphetamine Equivalent = Current Dose × Conversion Factor
If the target is Methylphenidate Equivalent, the calculator applies another factor:
Methylphenidate Equivalent = Amphetamine-Equivalent Dose × 2
Combining the two steps gives:
Methylphenidate Equivalent = Current Dose × Conversion Factor × 2
These equations describe what the calculator does mathematically. They should not be interpreted as universally accepted prescribing formulas.
Worked Example 1: Adderall to Amphetamine Equivalent
Suppose the user enters:
- Medication: Adderall
- Daily dose: 20 mg/day
- Target: Amphetamine Equivalent
The calculator assigns Adderall a factor of 1.0.
The calculation is:
20 × 1.0 = 20 mg/day
The estimated result is therefore:
20.0 mg/day amphetamine equivalent
Again, this is an educational calculation rather than a clinical switching instruction.
Worked Example 2: Methylphenidate to Amphetamine Equivalent
Suppose the user enters:
- Medication: Methylphenidate
- Daily dose: 20 mg/day
- Target: Amphetamine Equivalent
The calculator uses a factor of 0.5.
Calculation:
20 × 0.5 = 10 mg/day
The tool therefore displays approximately:
10.0 mg/day amphetamine equivalent
This is the calculator's mathematical output, not a recommendation for changing medication.
Worked Example 3: Methylphenidate to Methylphenidate Equivalent
Now suppose:
- Medication: Methylphenidate
- Daily dose: 20 mg/day
- Target: Methylphenidate Equivalent
First:
20 × 0.5 = 10
Then, because the target is methylphenidate equivalent:
10 × 2 = 20 mg/day
The calculator therefore returns:
20.0 mg/day
This example demonstrates that the calculator's target selection affects the final number.
Worked Example 4: Vyvanse
Consider a hypothetical entered dose of:
30 mg/day Vyvanse
The calculator uses the factor 0.3.
For an amphetamine-equivalent comparison:
30 × 0.3 = 9 mg/day
For a methylphenidate-equivalent comparison:
9 × 2 = 18 mg/day
Therefore, the calculator produces:
- 9.0 mg/day amphetamine equivalent, or
- 18.0 mg/day methylphenidate equivalent
depending on the selected target.
These values are mathematical outputs from the calculator and should not be used independently to determine a prescription.
Understanding the Difference Between an Estimate and a Clinical Conversion
One of the most important points about this calculator is that an equivalent number is not necessarily an equivalent treatment.
Two stimulant medications can have similar calculated equivalence while producing different clinical effects because of differences in absorption, timing, formulation, active ingredients, and duration.
Clinical resources give examples of medication-specific conversions but also caution that many stimulant products should not be substituted simply on a mg-for-mg basis. For some products, clinicians are advised to discontinue the previous medication and titrate the replacement according to its own dosing instructions.
This is why a mathematical conversion can be useful for discussion and education, while still being inappropriate as a standalone dosing decision.
Why Extended-Release Formulations Matter
One major limitation of simple dose-equivalence calculations is the difference between immediate-release and extended-release medications.
An immediate-release medication may produce a shorter period of action and a faster rise and fall in drug concentration. An extended-release medication is designed to provide a different exposure profile.
Concerta, for example, is an extended-release methylphenidate formulation. Clinical guidance includes product-specific examples for conversion from immediate-release methylphenidate to Concerta, rather than relying solely on a generic stimulant-to-stimulant multiplier.
Therefore, when evaluating a medication switch, the total daily milligram amount is only one part of the picture.
Factors That Can Affect a Real Medication Switch
A healthcare professional may consider a range of factors before changing stimulant therapy.
Age
Pediatric and adult patients may have different dosing requirements, response patterns, and safety considerations.
Treatment Response
The goal of stimulant treatment is not simply to reach a mathematically equivalent dose. The clinician generally considers symptom control, functional improvement, duration of benefit, and adverse effects.
Blood Pressure and Heart Rate
Stimulant therapy can affect cardiovascular parameters. Appropriate medical assessment and monitoring may therefore be important for some patients.
Sleep
The timing and duration of stimulant effects can influence sleep. A long-acting product may behave differently from an immediate-release product even when the underlying stimulant category is similar.
Appetite and Weight
Reduced appetite can occur with stimulant treatment, making nutritional status and weight relevant to ongoing management.
Mental Health and Other Medical Conditions
Individual psychiatric and medical circumstances may affect medication selection and monitoring.
Other Medications
Drug interactions and other prescribed or non-prescribed substances can influence the safety or effectiveness of a medication plan.
These considerations reinforce why an online equivalence calculator should be viewed as an educational aid rather than a replacement for individualized prescribing.
Benefits of Using an Online Stimulant Conversion Calculator
Although it should not be used to self-adjust medication, a stimulant conversion calculator can still be useful.
Quick Educational Comparison
The tool can rapidly demonstrate how different doses compare according to a predefined mathematical model.
Supports Medication Discussions
Patients can use an estimated comparison as a starting point for questions to discuss with a prescriber or pharmacist.
Makes Calculations Easier to Understand
Instead of manually multiplying doses, the calculator performs the arithmetic automatically.
Reduces Simple Arithmetic Errors
When comparing several scenarios, automated calculations can make it easier to avoid basic mathematical mistakes.
Helps Explain Equivalent-Dose Concepts
The tool can help users understand why the same milligram amount does not necessarily mean the same medication effect.
Important Safety Information
This calculator is intended for educational purposes only.
Do not use the calculated result to:
- Start a new stimulant
- Increase a stimulant dose
- Reduce a stimulant dose
- Stop a prescribed medication
- Substitute one prescription stimulant for another
- Adjust medication timing
- Determine a personal treatment plan
Prescription stimulant conversion should be determined by an appropriately qualified healthcare professional.
This is particularly important because clinical substitution guidance can involve medication-specific conversion tables, titration schedules, release characteristics, and patient monitoring rather than a single universal conversion ratio.
If you are already taking a prescription stimulant and are considering changing medications, speak with your prescriber or pharmacist before making any change.
Stimulant Conversion Comparison Table
The following table summarizes the mathematical factors used by this particular calculator.
| Current Stimulant | Calculator Factor | Target: Amphetamine | Target: Methylphenidate |
|---|---|---|---|
| Adderall | 1.0 | Dose × 1.0 | Dose × 1.0 × 2 |
| Dextroamphetamine | 1.2 | Dose × 1.2 | Dose × 1.2 × 2 |
| Amphetamine | 1.0 | Dose × 1.0 | Dose × 1.0 × 2 |
| Methylphenidate | 0.5 | Dose × 0.5 | Dose × 0.5 × 2 |
| Concerta | 0.5 | Dose × 0.5 | Dose × 0.5 × 2 |
| Vyvanse | 0.3 | Dose × 0.3 | Dose × 0.3 × 2 |
This table describes the calculator's internal model, not a universally accepted clinical conversion standard.
Common Mistakes When Comparing Stimulant Doses
Assuming Equal Milligrams Mean Equal Potency
They do not necessarily mean the same thing across different medications.
Ignoring Formulation
Immediate-release and extended-release products can have substantially different pharmacokinetic profiles.
Treating an Estimate as a Prescription
An online calculation cannot account for a person's complete medical history.
Switching Without Professional Guidance
A numerical estimate should never be treated as permission to change medication.
Focusing Only on the Dose
Clinical treatment also involves symptom response, adverse effects, treatment duration, comorbidities, and monitoring.
Who Can Benefit From This Calculator?
The tool can be useful for people who want to better understand stimulant dose comparisons for educational purposes, including patients preparing for a conversation with a healthcare professional, caregivers learning about medication terminology, students studying pharmacology concepts, and readers researching differences between stimulant categories.
Healthcare professionals may also encounter conversion discussions during formulary changes or medication shortages, but actual therapeutic substitution should rely on authoritative prescribing information and professional judgment rather than an online calculator alone. Contemporary literature on stimulant substitution highlights the need to consider pharmacologic differences, formulation, duration of action, and patient-specific risks.
Frequently Asked Questions
1. What does a stimulant conversion calculator do?
A stimulant conversion calculator estimates a numerical equivalent between selected stimulant medications based on predefined conversion factors. It provides an educational comparison and does not establish an individualized prescription.
2. Is the result a recommended dose?
No. The result is not a recommended dose or a medical instruction. It is an estimated mathematical comparison generated from the factors programmed into the calculator.
3. Can I switch medications using the calculated number?
No. You should not switch stimulant medications based solely on an online calculation. Medication substitution can require individualized titration and consideration of formulation and pharmacokinetics.
4. Does 20 mg of one stimulant equal 20 mg of another?
Not necessarily. Different stimulant medications have different active ingredients, formulations, pharmacokinetic properties, and clinical effects.
5. What medications are included in this calculator?
The calculator includes Adderall, dextroamphetamine, amphetamine, methylphenidate, Concerta, and Vyvanse.
6. What is an amphetamine equivalent?
In this calculator, an amphetamine equivalent is an intermediate comparison value calculated by multiplying the entered daily dose by the selected medication's programmed conversion factor.
7. What is a methylphenidate equivalent?
For this calculator, the methylphenidate-equivalent result is obtained by first calculating the amphetamine-equivalent value and then multiplying it by 2.
8. Why is Vyvanse calculated differently?
The calculator assigns Vyvanse a factor of 0.3 because it treats the medication differently within its internal educational conversion model. This factor should not be interpreted as a universal prescribing conversion.
9. Does the calculator account for immediate-release and extended-release formulations?
The calculator includes both methylphenidate and Concerta as separate selections, but its calculation is still based on a simplified factor. It does not fully model all pharmacokinetic differences between formulations.
10. Is Concerta directly interchangeable with Ritalin?
Not automatically. Although both involve methylphenidate, their release characteristics differ. Clinical conversion can require product-specific guidance rather than relying on a generic equivalence calculation.
11. Can this calculator be used for children?
The calculator does not provide individualized pediatric dosing. Children may require age-, weight-, response-, and condition-specific prescribing decisions, so pediatric stimulant changes should be managed by the child's healthcare professional.
12. Can this tool be used for adults?
Adults may use the tool for educational comparison, but the calculated result should still not be used to determine or change an individual treatment regimen.
13. Why can two equivalent doses feel different?
Equivalent numerical doses may still produce different experiences because of absorption, duration, release mechanism, formulation, individual metabolism, and other patient-specific factors.
14. What should I do if my medication is unavailable?
Contact your prescriber or pharmacist. During stimulant shortages, substitution can involve medication-specific considerations and titration rather than simply selecting a numerical equivalent from an online tool.
15. How accurate is this Stimulant Conversion Calculator?
The calculator is accurate in performing the mathematical operations programmed into it, but the resulting equivalence should be considered an approximate educational estimate, not a clinically validated universal conversion. Real-world medication substitution requires professional assessment.
Final Thoughts
The Stimulant Conversion Calculator offers a convenient way to explore approximate dose relationships among several commonly recognized stimulant medications. By selecting a medication, entering the current daily dose, and choosing an amphetamine or methylphenidate target, users can quickly see the corresponding value generated by the calculator's conversion model.
The most important point is that the calculated figure is a comparison tool, not a treatment recommendation. Clinical evidence and guidance show that stimulant substitution can depend on factors such as active ingredient, formulation, duration, pharmacokinetics, patient characteristics, cardiovascular considerations, and treatment response.
Use the calculator to improve your understanding, prepare questions, or explore stimulant-equivalence concepts. For any actual medication change, dose adjustment, discontinuation, or substitution, rely on advice from a qualified healthcare professional.