Caffeine Intake Calculator
Find out how much caffeine is safe for you based on body weight, and see practical equivalents in cups of coffee and espresso shots.
Caffeine Guidelines
The FDA and most health bodies recommend no more than 400 mg/day for healthy adults. The calculator uses 5.7 mg/kg as a weight-based cap, but never exceeds 400 mg.
Caffeine Content of Common Drinks
| Drink | Caffeine (mg) |
|---|---|
| Coffee (8 oz / 240 ml) | ~95 |
| Espresso (1 shot) | ~63 |
| Black tea (8 oz) | ~47 |
| Green tea (8 oz) | ~28 |
| Energy drink (8 oz) | ~80 |
| Pre-workout supplement | 150–300 |
Caffeine and Performance
Caffeine is one of the most studied ergogenic aids. At the right dose it improves endurance, strength output, reaction time, and focus. It works by blocking adenosine receptors in the brain, reducing perceived effort and fatigue.