Caffeine Calculator

A standard cup of coffee (125 ml) contains about 125 mg of caffeine. The exact amount varies depending on the type of coffee and brewing method.

EFSA considers up to 400 mg of caffeine per day safe for healthy adults, which equals approximately 3–4 cups of coffee.

A cup of tea contains on average about 50 mg of caffeine. Black tea typically has more caffeine than green tea.

A typical 250 ml energy drink contains about 80 mg of caffeine. Always check the product label as values can vary.

The biological half-life of caffeine is about 6 hours — after this time, half of the consumed dose remains in the body. After 12 hours, about 25% remains.

It is recommended to avoid caffeine for at least 6 hours before bedtime. Pregnant women should limit intake to 200 mg per day.

This ratio shows the individual caffeine load relative to body mass. The safe level for adults is up to approximately 5–6 mg/kg of body weight.

Regular consumption of large amounts of caffeine can lead to mild physical dependence and withdrawal symptoms such as headaches when stopped abruptly.

A standard can of cola (355 ml) contains about 34 mg of caffeine — much less than coffee, but worth factoring into your daily total.

Caffeine blocks adenosine receptors responsible for feelings of sleepiness. Consuming it in the afternoon or evening can significantly impair the ability to fall asleep and reduce sleep quality.