How many litres of water does an adult need per day from all sources?

Food medium Data from 2023

Guess before you scroll — the answer is below

Answer in litres. Shorthand like 9m or 1.2bn works.

The answer

3 litres

Roughly 2.7.

EFSA puts adequate daily water intake at about 2.0 litres for women and 2.5 for men, averaging around 2.7 across sources — and roughly 20-30% of it comes from food, not drinks. The famous "eight glasses" rule has no scientific origin anyone can find.

Where this number comes from

Source European Food Safety Authority dietary reference values
Figure refers to 2023
Last checked
Unit litres

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