Calculate your water needs

Estimate how much water to drink each day based on your weight, your activity and the climate. Free and instant.

Your details

Climate

Your water need

2.7 L/day
about 11 glasses of water
Base (based on your weight)2.3 L
Added for activity + climate+0.4 L

The water in food and other drinks counts too. Drink regularly, without waiting until you are thirsty.

How much water to drink Hydration & sport

How are your water needs calculated?

The calculator starts from a base of about 33 ml of water per kilo of body weight, then adds a supplement based on your physical activity (sweating increases losses) and the climate (heat does too). This gives an estimate of your daily need for drinks.

Why is good hydration important?

Water regulates body temperature, carries nutrients and allows waste to be eliminated. Even mild dehydration causes tiredness, headaches and poor concentration. Because thirst arrives too late, it is better to drink regularly.

To find out more, read our guides on how much water to drink per day and hydration and sports performance.

Frequently asked questions

How much water should you drink per day?
On average 1.5 to 2.5 L of drinks depending on weight, activity and climate. Our calculator personalises this estimate. The water in food (fruit, vegetables, soups) comes on top of that.
Do coffee and tea count?
Yes, despite their mild diuretic effect, they contribute to hydration. Water is still the best drink, with no sugar or calories.
How do I know if I am drinking enough?
A good guide: clear, regular urine. Dark, infrequent urine is a sign you need to drink more.
This tool provides an estimate for information only and does not replace the advice of a healthcare professional. No data you enter on this page is collected or stored.