Caffeine calculator
For healthy adults, EFSA considers up to 400 mg of caffeine a day safe, and up to 200 mg during pregnancy and breastfeeding. The calculator adds up the caffeine in what you have had to drink and eat today and compares the total with that level.
The limits come from the 2015 EFSA scientific opinion. For adults: 400 mg a day and up to 200 mg in a single dose. For children and teenagers, EFSA proposes 3 mg per kilogram of body weight a day.
The caffeine per serving is a typical value from USDA FoodData Central, EFSA and published measurements. The real spread is wide: espresso from different coffee shops can differ several-fold.
How it works
- Pick the drinks and foods you have had today and the number of servings.
- Say who the calculation is for: an adult, a pregnant or breastfeeding woman, or a child or teenager.
- Compare the total with the safe level. If it is higher, start with the strongest serving: it is the easiest to swap.
Where the caffeine is
Per serving, the most comes from Turkish coffee, filter coffee and energy drinks: a 450 ml can has about 140 mg. A cup of black tea has about 40 mg, a can of cola 30–40 mg, and a quarter of a bar of dark chocolate about 20 mg.
In the EU, drinks other than tea and coffee with more than 150 mg of caffeine per liter must carry the warning “High caffeine content. Not recommended for children or pregnant or breast-feeding women”, with the caffeine content given in mg per 100 ml.
| Who | Safe level according to EFSA |
|---|---|
| Adults | 400 mg a day, up to 200 mg at a time |
| Pregnancy and breastfeeding | 200 mg a day |
| Children and teenagers | 3 mg per kilogram of body weight a day |
Frequently asked questions
- How many cups of coffee a day are safe?
- For an adult, four to five 200 ml cups of filter coffee, each with roughly 80–90 mg. Strong Turkish coffee has more caffeine, so fewer cups fit.
- Does decaf coffee contain caffeine?
- A little: about 2 mg per cup. It makes almost no difference to your daily total.
- Why is the limit lower in pregnancy?
- Caffeine crosses the placenta and passes into breast milk, and during pregnancy the body clears it more slowly. EFSA considers up to 200 mg a day safe during this time.
Further reading
- Coffee: how much you can drink and what adds calories
- Energy drinks: what’s in the can
- Caffeine and adenosine: why coffee wakes you up
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This calculator gives an estimate for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.