Water intake calculator
Look up the adequate daily intake of water for adults and see how it splits between drinks and food.
Adequate intake for your group
Choose your group and enter your age, then continue.
What the numbers mean
There is no accurate personal formula for water, so this page does not invent one. It reports the Adequate Intake that the National Academies set from what healthy, normally hydrated adults actually drink.
| Adult group | Total water | From drinks | From food |
|---|---|---|---|
| Men | 3.7 L | 3.0 L | about 0.7 L |
| Women | 2.7 L | 2.2 L | about 0.5 L |
Worked example
For an adult man the total is 3.7 L, of which 3.0 L comes from drinks. At 250 ml per glass that is 3000 ÷ 250 = 12 glasses. For an adult woman, 2200 ÷ 250 = 8.8 glasses. Tea, milk and other drinks count towards the drinks figure, and so does the water in food.
Limits
- Needs rise with hot weather, sweating and exercise. This tool does not adjust for them.
- Pregnancy and breastfeeding have their own values and are not covered.
- If a clinician has told you to limit fluids, for example for heart or kidney disease, follow that advice.
Thirst is a reliable guide for most healthy adults. Pale yellow urine is a rough everyday check.
Who this tool is for
This tool is for healthy adults aged 20 and older. It is not for use during pregnancy or breastfeeding, and it does not diagnose any condition, suggest medicine doses, set weight-loss targets or write personal meal plans. If you have a medical condition, or a result worries you, speak to a doctor or registered dietitian.
Your numbers stay in your browser. They are not sent anywhere, saved, or added to the page address. See our privacy policy.
Sources
- National Academies: Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2005) — adequate intake values
See the editorial methodology for how we check sources.