Enter your weight and exercise time to get an estimate of how much water to drink per day. This is a rule of thumb only. Estimate only, not medical advice.
Result
This result is an estimate only. Check with your bank or the relevant authority before making decisions.
How it is calculated
This is a rule of thumb, not a medical measurement:
Base water = body weight (kg) × 35 ml
Exercise extra = exercise minutes ÷ 30 × 500 ml
The total is shown in litres
Glasses = litres ÷ 0.25, rounded up
Estimate only, not medical advice.
Worked example
60 kg, no exercise: 60 × 35 = 2,100 ml = 2.1 litres, or 9 glasses
60 kg, 60 minutes of exercise: 2,100 + 1,000 = 3,100 ml = 3.1 litres, or 13 glasses
Why your number may differ
This is a rule of thumb (about 35 ml per kg). Hot weather and illness change how much water you need, and food also provides water. Estimate only, not medical advice.
Frequently asked questions
Is this an exact rule?
No. It is a rule of thumb of about 35 ml per kg of body weight. Hot weather and illness change your needs, and food also provides water.
How is exercise counted?
The calculator adds 500 ml for every 30 minutes of exercise.
How are glasses calculated?
Litres divided by 0.25 (one 250 ml glass), rounded up.