Nutrition & supplements
How much caffeine can you safely take per day?
Maximum daily caffeine and pre-workout dose based on body weight, with espresso equivalents.
Quick answer
Caffeine is the world’s most used performance enhancer — and one of the few backed by overwhelming evidence for both mental alertness and physical output. But the right amount is personal: it scales with body weight, which is exactly what this calculator does using EFSA’s safety thresholds (3 mg/kg per single dose, about 5.7 mg/kg per day, capped around 400 mg for healthy adults).
Safe daily maximum
400 mg
- Maximum single dose
- 225 mg
- Pre-workout (30-60 min before)
- 225 – 450 mg
- Espresso equivalent (~80 mg)
- 5 shots per day
EFSA limits: 3 mg/kg per single dose, 5.7 mg/kg per day (max ~400 mg for a healthy adult). During pregnancy the limit drops to 200 mg. Avoid caffeine 6-8 hours before sleep. Not a substitute for medical advice.
How it works
For context on real doses: an espresso carries roughly 80 mg, a filter coffee mug 90-140 mg, an energy drink 80-160 mg, and pre-workout supplements 150-300 mg per scoop — it adds up faster than most people think. For sports performance, research supports 3-6 mg/kg taken 30-60 minutes before training. And because caffeine’s half-life is 5-6 hours, that 4 PM coffee is still half in your blood at 10 PM: if sleep matters to you, front-load your intake in the morning.
Frequently asked questions
How much caffeine is in an espresso vs energy drinks?+
A single espresso has about 60-80 mg; a double, 120-160 mg. A standard 250 ml energy drink carries ~80 mg, but the 500 ml cans reach 160-200 mg. Filter and moka coffee sit at 90-140 mg per mug. Tea has 30-50 mg, cola about 35 mg, and dark chocolate adds 20-60 mg per 100 g.
When should I take caffeine before a workout?+
Blood levels peak 30-60 minutes after ingestion, so that’s the window to aim for. Research supports 3-6 mg/kg for strength and endurance benefits — for a 75 kg person, 225-450 mg, though regular coffee drinkers may need the higher end. If you train in the evening, weigh the performance boost against the sleep cost: sleep loss hurts progress more than caffeine helps.
Why doesn’t coffee affect me anymore?+
Tolerance: with regular intake, your brain grows more adenosine receptors to compensate, blunting the alerting effect within 1-2 weeks of steady use. The fix isn’t more caffeine — it’s a reset: 1-2 weeks at low or zero intake restores sensitivity. Expect 2-4 days of headaches and low energy when quitting; tapering gradually softens it.
Is 400 mg of caffeine a day really safe?+
For healthy adults, yes — that’s the ceiling EFSA and FDA agree on, roughly 4-5 espressos spread across the day. The limit drops to 200 mg/day during pregnancy, and people with heart arrhythmias, anxiety disorders or reflux should stay lower. Warning signs you’ve overshot: jitters, racing heart, anxiety and disturbed sleep. This is general information, not medical advice.
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