Caffeine Calculator
The caffeine dose that actually boosts performance for your body weight — and the daily limit to stay under.
Your results
Shop pre-workoutHow much caffeine should you take before a workout?
This caffeine calculator gives you the performance-effective pre-workout dose for your body weight — and the daily ceiling you should stay under. Caffeine is one of the few supplements with overwhelming evidence: it measurably improves strength, endurance and power when dosed correctly.
How it works
The International Society of Sports Nutrition's position stand concludes caffeine improves performance at 3–6 mg per kg of body weight, taken about 60 minutes before exercise. Below 3 mg/kg effects are inconsistent; above 6 mg/kg side effects (jitters, anxiety, racing heart) grow faster than benefits. For daily safety, the European Food Safety Authority sets 400 mg per day as the level with no health concerns for healthy adults, with single doses up to 200 mg.
Frequently asked questions
How much caffeine is in my pre-workout?
Most pre-workouts contain 150–300 mg per serving — check the label and count it toward your daily total, along with coffee (~95 mg per cup) and energy drinks (~80–160 mg).
Why can't I sleep after evening training?
Caffeine's half-life is around five hours — a 4 pm dose of 200 mg still leaves ~100 mg circulating at 9 pm. Keep caffeine out of the last 8 or so hours before bed, or train evenings without it.
Does tolerance kill the benefits?
Habitual users still get a performance boost, but it blunts somewhat. Some athletes taper for a week before competition to resensitise. Cycling isn't required for everyday training.
Who should avoid high doses?
Anyone pregnant, sensitive to caffeine, with heart conditions or high blood pressure should stay well below these numbers and talk to a doctor first.
References
- Guest NS, VanDusseldorp TA, et al. International Society of Sports Nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18(1):1.
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the safety of caffeine. EFSA Journal. 2015;13(5):4102.
Related
These results are estimates for healthy adults and are not medical advice. Consult a health professional before making major changes to your diet or training.
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