Water Intake Calculator
Calculate how much water to drink daily based on body weight and activity.
Last updated: August 2026
Daily water
2.7 L
In 250 ml glasses
11
Standard glass size
Millilitres
2,670 ml
General guide: 33 ml per kg of body weight plus 12 ml per minute of exercise. Individual needs vary with climate, sweat and health.
How it works
Litres = weight kg × 0.033 + exercise minutes × 0.012.
Example: 70 kg + 30 min exercise → ≈ 2.67 litres.
Frequently Asked Questions
How much water should I drink a day?
A common guide is 33 ml per kg of body weight, plus extra for exercise and hot climates. A 70 kg person needs about 2.3 litres at rest.
Does food count toward water intake?
Yes. Food provides roughly 20% of daily water, so drinks alone need only about 80% of the total target.
Can I drink too much water?
Drinking far beyond your needs is possible but rare. Your kidneys handle about 1 litre per hour; very large intakes can cause water intoxication.
Do I need more water in summer or when exercising?
Yes. Sweat increases in heat and during exercise, so add roughly 12 ml per minute of activity and drink extra on hot days or when your urine is dark.