Water Intake Calculator
Daily water target from weight, exercise and climate.
Your result appears here
Fill in the fields on the left and press Calculate. The answer, the breakdown and a copy button all land in this card.
How it is calculated
Water (ml) = weight (kg) × 33 + (exercise minutes ÷ 30 × 350), adjusted for climate
Food contributes roughly 20% of your fluid intake, so the drinking target shown is slightly below total fluid needs.
Worked example
At 70 kg with 30 minutes of exercise in a moderate climate: 2,310 + 350 = about 2.66 litres, which is roughly 11 glasses of 250 ml.
Questions people ask
Yes, all fluids count towards hydration, and food supplies a fair share too. The classic "eight glasses" advice was never based on strong evidence.
Pale straw-coloured urine and infrequent thirst are good everyday signals. Dark urine and headaches suggest you need more.
Rarely, but yes — very large volumes in a short time can dilute blood sodium dangerously. Spread intake through the day.