Caffeine Intake Calculator
Estimate caffeine intake limits based on body weight.
Enter your details and calculate.
The other number worth knowing
The printable chart: 30+ foods ranked by protein per 100 calories.
Related Tools
Best Caffeine Supplements
From pure caffeine powder to fully-dosed pre-workouts — find the right source for your calculated intake.
FAQs
How much caffeine is safe per day?
Up to ~400mg/day is generally considered safe for healthy adults. For performance, research supports 3–6mg per kg of bodyweight taken before training — the calculator scales this to your weight so you don't overshoot.
When should I take caffeine before a workout?
Plasma caffeine peaks roughly 30–60 minutes after ingestion, so taking it 30–60 minutes pre-training aligns the peak with your session. See our caffeine guide for the full evidence.
Why does caffeine stop working — and how do I protect my sleep?
Tolerance builds with daily use; occasional short breaks restore sensitivity. Caffeine's half-life is ~5–6 hours, so a late-afternoon dose still has meaningful levels in your system at bedtime — keep a cutoff of at least 8 hours before sleep.
Where to buy on Amazon
Products discussed on this page. Outside the US the links open your local Amazon store where it carries the product; stock and price differ between stores. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.