Nootropic Dosing Calculator — Racetams, Modafinil & Noopept

Last updated: June 2026

About the Nootropic Dosing Calculator

The Nootropic Dosing Calculator is a free educational tool that works out a per-dose and daily nootropic dose. It is not medical advice. You pick a compound — piracetam, aniracetam, oxiracetam, pramiracetam, phenylpiracetam, noopept, modafinil, armodafinil, L-theanine or alpha-GPC — enter your bodyweight for racetams, and choose a tolerance level. The calculator returns a per-dose figure in mg, how many doses per day, the redose timing based on the compound's half-life, the daily total, and stimulant cycling guidance. Free, no login.

It is built for people who want a quick, sensible estimate of typical nootropic doses before they commit — whether you are looking at a racetam scaled to your bodyweight, or a fixed-dose compound such as modafinil or noopept. Every figure it shows is a typical human-use range, not a personalised prescription, and the right dose for you always depends on your own response and a clinician's advice.

How to use it

Pick your compound from the list. Racetams (piracetam, aniracetam, oxiracetam, pramiracetam, phenylpiracetam) are scaled by bodyweight; modafinil, armodafinil, noopept, L-theanine and alpha-GPC use standard fixed ranges.

If you picked a racetam, enter your bodyweight in kilograms or pounds — the calculator converts for you and scales the per-dose figure by mg/kg.

Choose a tolerance level — naive, regular or heavy. This applies a multiplier (about 0.7 for naive, 1.0 for regular, 1.3 for heavy) to the racetam per-dose figure. The output then shows your per-dose mg, doses per day, redose timing from the half-life, the daily total, and 5-on/2-off cycling guidance for stimulant-type compounds.

Worked example

Example

Compound: Piracetam

Bodyweight: 75 kg

Tolerance: Regular (multiplier 1.0)

Per-dose: ~24 mg/kg × 75 kg × 1.0 ≈ 1,800 mg per dose

Doses per day: 2×

≈ 3,600 mg daily · redose roughly every 8 hours

At 75 kg and regular tolerance, piracetam works out to roughly 24 mg/kg per dose, which is about 1,800 mg per dose. Taken twice a day that is about 3,600 mg daily. Piracetam has a relatively short half-life, so the calculator suggests redosing roughly every 8 hours to keep levels steady through the day. A naive user (0.7×) would land lower, around 1,260 mg per dose; a heavy user (1.3×) higher, around 2,340 mg per dose.

Racetams vs fixed-dose compounds

Not every nootropic is dosed the same way, and the calculator handles two groups differently.

Racetams (scaled): piracetam, aniracetam, oxiracetam, pramiracetam and phenylpiracetam are dosed roughly per kilogram of bodyweight. A heavier person needs more to reach the same exposure, so the calculator multiplies a typical mg/kg figure by your weight and your tolerance multiplier.
Fixed-dose compounds: modafinil, armodafinil, noopept, L-theanine and alpha-GPC are not weight-scaled. They sit in standard ranges regardless of bodyweight — for example modafinil 100–200 mg in the morning, armodafinil around 150 mg, and noopept 10–30 mg taken sublingually. For these the calculator shows the standard range rather than a bodyweight calculation.

That is why the bodyweight field only matters for racetams: for fixed-dose compounds, your weight does not change the dose.

Cycling stimulants

Some nootropics are stimulant-type and build tolerance quickly. Phenylpiracetam, modafinil and armodafinil all lose their edge if used every single day, because the body adapts.

5-on / 2-off: a common approach is five days on, two days off, so the effect stays noticeable instead of fading into baseline.
Morning only: these compounds have long-lasting wakefulness effects, so dosing in the morning helps avoid disrupting sleep.
Watch the build-up: if you find you need a higher dose for the same effect, that is tolerance — a sign to take a longer break rather than keep increasing.

Non-stimulant compounds such as the gentler racetams, L-theanine and alpha-GPC are generally used more steadily, but cycling is still a sensible habit. None of this is a recommendation to use any compound — it is general information about how people manage tolerance.

Frequently asked questions

How are racetam doses scaled by bodyweight and tolerance?

Racetams such as piracetam, aniracetam, oxiracetam, pramiracetam and phenylpiracetam are dosed roughly per kilogram of bodyweight. The calculator uses a typical mg/kg figure for the chosen compound and multiplies it by a tolerance factor — about 0.7 for a naive user, 1.0 for a regular user and 1.3 for a heavy user — then multiplies the per-dose figure by the number of doses per day to get a daily total. So a heavier person, or someone more tolerant, lands on a higher dose, and a lighter or naive person on a lower one. These are typical human-use ranges for education, not a personalised prescription.

Why are modafinil, noopept and similar compounds shown as fixed doses?

Modafinil, armodafinil and noopept are not dosed per kilogram of bodyweight. They are used within standard fixed ranges regardless of weight — for example modafinil around 100 to 200 mg in the morning, armodafinil around 150 mg, and noopept around 10 to 30 mg taken sublingually. L-theanine and alpha-GPC are likewise used in standard ranges. For those compounds the calculator shows the standard range rather than scaling by bodyweight, because that is how they are actually used.

Should I cycle stimulant nootropics?

Stimulant-type nootropics such as phenylpiracetam, modafinil and armodafinil build tolerance quickly, so their effect fades if used every day. A common pattern is to cycle them — for example five days on and two days off — and to take them in the morning only, so they do not interfere with sleep. Cycling is a way to keep the effect while limiting tolerance build-up. None of this is medical advice; talk to a clinician before using or stacking stimulants.

Is this calculator medical advice?

No. The Nootropic Dosing Calculator is an educational estimate only and not medical advice. The figures shown are typical human-use ranges with wide individual variation. Start low and assess your own response. Modafinil and armodafinil are prescription medicines in many countries. Talk to a clinician before starting, combining or stacking any nootropic or stimulant.

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Important: read before you use this

This is an educational estimate only — it is NOT medical advice. The per-dose and daily figures shown are typical human-use ranges with wide individual variation, not a recommendation for you specifically. Start low and assess your own response before considering more. Modafinil and armodafinil are prescription medicines in many countries and should only be used under a prescriber's supervision. Talk to a clinician before starting, combining or stacking stimulants or any nootropic, especially if you have a heart, blood-pressure, mental-health or sleep condition, or take other medicines. Do not use this tool to self-treat. Your own clinician always supersedes anything shown here. InjectBuddy is a maths and education tool, not a clinical service.