Water intake calculator
An adult of healthy weight needs 1 to 2.2 liters of water and other drinks a day, depending on sex and physical workload. The calculator takes the figure from Russia’s official physiological requirement norms, issued by Rospotrebnadzor in 2021.
The values are from table 7 of the guidelines MR 2.3.1.0253-21 (in Russian). They cover water and drinks, tea and coffee included. Water from food is counted separately.
EFSA and the US National Academies count total water, food included. EFSA sets adequate intakes of 2.0 liters a day for women and 2.5 liters for men, of which food typically supplies 20–30%. The National Academies set 2.7 and 3.7 liters, about 80% of it from drinks.
How it works
- Choose your sex and enter your age and how physically demanding your work is.
- See how much water and other drinks you need on an ordinary day.
- In hot weather, during exercise and when you are ill, drink more and let thirst guide you.
Why not 30 ml per kilogram
Neither “30 ml per kilogram of body weight” nor “two liters a day” appears in the norms. Both are simplifications that lost the main point along the way: much of your water comes with food, and thirst sets the amount. The story of the two liters is told in How much water to drink per day.
In a healthy adult, thirst kicks in before any real water deficit develops. Conscious tracking matters for older people, young children, in the heat and during hard physical work, and when a doctor has restricted fluids.
| Activity (factor) | Men / women, per day |
|---|---|
| 1.4 — very low: desk work, office | 1.3–1.4 L / 1.0–1.1 L |
| 1.6 — low: light work — shop assistant, driver, nurse | 1.5–1.6 L / 1.2–1.3 L |
| 1.9 — moderate: mechanic, machine operator, gardener | 1.8–1.9 L / 1.4–1.5 L |
| 2.2 — high: heavy physical labor | 2.1–2.2 L / 1.7–1.8 L |
| 65 and over | 1.4–1.5 L / 1.1–1.2 L |
Frequently asked questions
- Do tea, coffee and soup count?
- Tea, coffee, milk and other drinks count towards this figure. The Russian guideline (MR 2.3.1.0253-21) puts soup among the liquids that supply about 60% of water, and vegetables and fruit among solid food, about 40%. Pick one way of logging soup and keep to it.
- Should I drink more to lose weight?
- There is no special water target for weight loss. You need more in hot weather, during exercise and when you lose fluid through vomiting, diarrhea or fever.
- Can you drink too much water?
- Yes. Drinking several liters beyond thirst in a short time lowers the sodium in your blood. This is hyponatremia, and it is dangerous. On long workouts it is safer to drink to thirst than to a schedule.
Further reading
- How much water to drink per day and where the two liters came from
- Alkaline water: what the stomach does to it
- Caffeine calculator
More calculators: Keto calculator, Caffeine calculator, Recipe calorie calculator, Exercise calorie calculator.
This calculator gives an estimate for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.