Water intake calculator

How much water to drink each day

Choose your sex, and whether you're pregnant or breastfeeding, to see roughly how much water to drink each day. The figures are based on the adequate intakes set by the European Food Safety Authority (EFSA) for adults in a mild climate who are moderately active.

How the figure is worked out

EFSA's adequate intake for total water is 2.0 litres a day for women and 2.5 litres a day for men. It adds 0.3 litres a day in pregnancy and 0.7 litres a day while breastfeeding.

Total water includes the water in food. EFSA estimates that about 20% comes from food, so the calculator shows 80% of the total as the amount to drink. It also shows that amount in 250 ml glasses, rounded to the nearest glass.

Worked examples

For a woman who isn't pregnant or breastfeeding, total water is 2.0 litres a day. About 80% of that, 1.6 litres, should come from drinks, which is about 6 glasses.

For a man, total water is 2.5 litres a day, so about 2.0 litres from drinks, or 8 glasses. While breastfeeding, a woman needs 2.7 litres in total, about 2.2 litres from drinks, or 9 glasses.

When you need more

These are adequate intakes for typical conditions. You need more in hot weather, when you exercise or sweat a lot, and when you're ill with a fever, vomiting or diarrhoea.

All drinks count, including tea, coffee, milk and sugar-free squash, though water is the healthiest choice. Pale yellow urine is a simple sign you're drinking enough.

This isn't medical advice. Some conditions, such as heart or kidney problems, need a different fluid intake, so follow what your GP or specialist tells you.

Inputs for the water intake calculator

Sex

EFSA sets different adequate intakes for women and men because of differences in average body size and energy use.

Pregnant or breastfeeding?

Adds 0.3 litres a day of total water in pregnancy or 0.7 litres a day while breastfeeding. Only shown if you choose female.

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