Caffeine Limit
Calculator
Results
- Upper caffeine intake (mg/day)
- 420
- Moderate caffeine intake (mg/day)
- 210
- Equivalent espresso shots (80 mg each)
- 5.25
Nutrition results
| Upper caffeine intake (mg/day) | 420 |
| Moderate caffeine intake (mg/day) | 210 |
| Equivalent espresso shots (80 mg each) | 5.25 |
formula-map diagram
- Upper caffeine intake (mg/day)
- 420
- Moderate caffeine intake (mg/day)
- 210
- Equivalent espresso shots (80 mg each)
- 5.25
Nutrition formula map
Formula
upper intake = body weight kg × 6 mg/kg (moderate = 3 mg/kg)= 420
Note
Simplified nutrition model using standard reference constants (protein and carbohydrate 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g, 1 kg of body fat about 7700 kcal, salt to sodium factor 0.393). Real energy needs and body composition changes vary between individuals. This is not medical, dietetic or nutritional advice; consult a qualified health professional before changing your diet.
More in Nutrition and diet
See all →Frequently asked questions
How is a safe caffeine limit calculated from body weight?+
The calculator generally applies a rate such as roughly 3-6 mg of caffeine per kilogram of body weight for adults, or references established flat limits like 400 mg/day, adjusting for weight where a per-kilogram guideline is used.
Why do caffeine guidelines sometimes use body weight and sometimes a flat number?+
Flat limits like 400 mg/day are based on general adult population studies and are simpler to communicate, while weight-based guidelines account for the fact that smaller individuals reach a given blood caffeine concentration from a smaller absolute dose, which matters more for adolescents or lower body weights.
Why is the recommended limit much lower for pregnant women?+
Caffeine crosses the placenta and the fetus metabolizes it much more slowly than an adult does, so major health organizations recommend limiting intake to around 200 mg per day during pregnancy regardless of body weight, well below the general adult guideline.
Does this calculation account for caffeine from all sources?+
The limit itself covers total daily caffeine regardless of source, but the calculator only tells you the ceiling — you need to separately add up coffee, tea, energy drinks, soda, chocolate, and some medications to compare your actual total intake against the calculated limit.
Is staying under the calculated limit a guarantee of no side effects?+
No, individual caffeine sensitivity varies considerably due to genetics, tolerance, and other factors, so some people experience jitteriness, anxiety, or sleep disruption at doses below the general safe limit, while regular consumers may tolerate more — treat the number as a population-level guideline, not a personal guarantee.