Water Intake Calculator
Estimate a daily water target from your weight and exercise — about 33 ml per kg, plus a bump for activity.
Reviewed by the OmniCalc teamMethod verified 2026-07-01
2.31L
Water 2.31 litres per day≈ 2,310 ml per day
Show steps
- Base: weight × 33 = 70 kg × 33 = 2,310 ml.
- Exercise: (0 min ÷ 30) × 350 = 0 ml.
- Total: 2,310 ml + 0 ml = 2,310 ml = 2.31 L per day.
General guideline only — not medical advice. Real water needs vary with climate, health, diet and individual factors.
How to use the water intake calculator
- 1Enter your weight in kilograms.
- 2Add your exercise minutes per day (0 if none).
- 3Read the daily target in litres, with the maths under Show steps.
A general guideline, not medical advice
This estimate leans on a common rule of about 33 ml/kg and is meant as a starting point, not a prescription. Real water needs shift with climate, health, diet and activity. For advice specific to you, talk to a clinician.
Frequently asked questions
How is the water intake estimated?
It uses a common guideline of about 33 ml of water per kilogram of body weight, then adds roughly 350 ml for every 30 minutes of exercise: dailyMl = weight × 33 + (minutes ÷ 30) × 350.
Is 33 ml per kg an exact rule?
No. It is a widely used rule of thumb, not a precise medical requirement. Real needs shift with climate, altitude, health, diet, pregnancy and how much you sweat. Treat the result as a starting point.
Does food and other drinks count?
Yes — a good share of daily fluid comes from food, tea, coffee and other drinks. This figure is a total hydration target, so you do not have to drink it all as plain water.