Get a rough daily fluid target based on your weight and activity, in line with health-authority guidance. A general estimate, not a strict rule. No sign-up.

A rough daily target

2.0–2.3 litres of fluid / day

About 8 to 9 cups, from all drinks.

Food gives you roughly a fifth of your water too, so you do not need every drop from drinks.

This is a general estimate from body weight, in line with health-authority guidance of around 2 litres of fluid a day for women (more with exercise or heat). It is not a strict rule: thirst and pale-yellow urine are good everyday guides. Some medical conditions need a specific fluid limit, so follow your doctor's advice if you have one. This tool is information, not medical advice.

How it works

Enter your weight and activity to get a rough daily fluid target.

The formula and sources

It estimates roughly 30 to 35 ml of fluid per kg of body weight, with about half a liter added for activity. For context, EFSA and NASEM put total daily water for women at around 2 liters from drinks, with more from food.

Assumptions

You are a generally healthy adult in a temperate climate.
Fluid comes from all drinks, and food adds more.

Limitations

This is a general estimate. Hot weather, exercise, illness, and pregnancy or breastfeeding raise your needs, and thirst plus pale urine are good everyday guides.

When to see a doctor

If you have a kidney or heart condition, your fluid target may be set for you medically. Follow that advice rather than a general estimate.

Primary sources

National Academies, Dietary Reference Intakes for Water, Potassium, Sodium, Chloride and Sulfate (2005). The report of record for daily water intake in adults.

Total water includes what you get from food, which is why a drinks-only target is lower than a total-water figure. Thirst and pale urine remain better day-to-day guides than any calculated number.

Calculator version 1.0. Figures and formula last checked 27 July 2026 against the sources above. This tool gives general information and does not replace advice from your own doctor.

Frequently asked questions

How much water should a woman drink a day?

Around 2 liters from drinks is a common guide, with more in heat, during exercise, illness, or pregnancy and breastfeeding. Your weight and activity fine-tune it.

Do tea and coffee count toward fluid?

Yes. In normal amounts they add to your daily fluid despite a mild diuretic effect. Water, milk and most drinks all count.

How do I know if I am drinking enough?

Pale, straw-colored urine and rarely feeling thirsty are good everyday signs. Dark urine usually means you need more.

Can you drink too much water?

Rarely, but a large excess can dilute blood sodium. If you have a heart or kidney condition, follow the fluid target set for you.

Water Intake Calculator for Women