Water intake calculator

Here is a realistic amount from all your drinks, with extra for exercise, heat and pregnancy.

Your details

Roughly how much to drink

1.6 litres

a day, from all drinks

Everyday amount from drinks1.6 litres
In pints2.8 pints
In 250 ml glasses6
In mugs (350 ml)4.6
UK fluid ounces / US cups (240 ml)56 / 6.7
Drunk so far500 ml, so about 1.1 litres to go

Tea, coffee, milk and squash all count. The easiest check is your wee: pale straw coloured is about right.

Some heart and kidney conditions need a fluid limit. If you have been told to limit drinks, stick with your own team's advice.

Litres and pints

Converting what you drink

The answer is shown in litres, UK pints, 250 ml glasses, 350 ml mugs, UK fluid ounces and US cups. A UK pint is 568 ml, bigger than an American pint (473 ml). Add what you have drunk so far, in any of those units, to see roughly how much is left for the day.

The working

From EFSA's total to your drinks

EFSA, the European food safety body, suggests a total water intake of 2.0 litres a day for women and 2.5 litres for men. About a fifth of that comes from food, so drinks provide around 80%: 1.6 litres for women and 2.0 litres for men. That lines up with the NHS advice of 6 to 8 glasses.

Extra	Added
Pregnancy	+300 ml
Breastfeeding	+700 ml
Each hour of exercise	about +500 ml
A hot day	about +500 ml

What counts

It does not all have to be water

Water, milk, tea, coffee and sugar free drinks all count. Tea and coffee are only mildly diuretic and still hydrate you overall. Fruit juice and smoothies count too, but keep them to 150 ml a day because of the sugar.

Am I drinking enough?

The colour check

Pale straw coloured wee is the simplest sign you are drinking enough. Dark yellow, strong smelling wee, a dry mouth, headaches or feeling dizzy suggest you need more. Older people feel thirst less, so regular drinks matter more.

Read with care

What this cannot tell you

Fluid limitsSome heart and kidney conditions need a limit; follow your own team.
IllnessDiarrhoea, sickness and fever need extra fluids and sometimes rehydration sachets.
ChildrenChildren need less in total but more relative to size.

Questions

Common questions

How much water should I drink a day?

About 1.6 litres from drinks for women and 2 litres for men, more when it is hot or you exercise. The NHS says 6 to 8 glasses.

Does tea and coffee count towards water intake?

Yes. They hydrate you overall, though very strong coffee in large amounts can make you wee more.

Can you drink too much water?

Yes, rarely. Drinking huge amounts very quickly, especially in long events, can lower blood sodium.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

If food feels hard

If eating, weight or food is on your mind a lot, you are not alone. Your GP can help, and Beat has a free helpline on 0808 801 0677 (England, weekdays 3pm to 8pm).