Caffeine Limit Calculator
Find your safe daily caffeine limit based on body weight. Enter your weight to get a recommended maximum per day (capped at the FDA's 400 mg for healthy adults) and a sensible per-dose limit.
- General guidance, not medical advice; sensitivity varies.
Formula
Daily limit = min(400 mg, 6 mg × weight); per-dose ≈ 3 mg × weight
- A common guideline is up to about 6 mg of caffeine per kg of body weight per day.
- The total is capped at 400 mg — the FDA's safe daily limit for healthy adults.
- A single dose is best kept to roughly 3 mg per kg to avoid jitteriness and a racing heart.
- Pregnant people should stay under 200 mg per day regardless of weight.
- Sensitivity varies; some people feel effects well below these limits.
70 kg adult
Inputs
- Body Weight: 70 kg
6 mg × 70 kg = 420 mg, which is capped at the 400 mg daily limit — about four cups of coffee. A sensible single dose is around 210 mg.
Frequently asked questions
How much caffeine is safe per day?
For most healthy adults, up to 400 mg daily is considered safe — roughly four cups of coffee. Lighter people should aim lower.
How is the limit based on weight?
It uses about 6 mg per kg of body weight per day, capped at 400 mg, with a per-dose guide of around 3 mg per kg.
What about during pregnancy?
Most guidelines recommend keeping caffeine under 200 mg per day during pregnancy. Check with your doctor.
What are signs I've had too much?
Jitteriness, anxiety, a fast or pounding heartbeat, insomnia, and an upset stomach are common signs.
Is this medical advice?
No. It's general guidance. Your tolerance depends on genetics, medications, and health conditions — consult a professional if unsure.
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