Hydration calculator for sports
How much water to drink before, during and after you play. It uses your weight, your sport, how long you play and how hot it is.
Drink this 2 to 4 hours before you play, so you start well hydrated and can still pass it out.
That is about 130 ml every 15 minutes. Small, regular sips work better than a lot at once.
Over the next few hours, to replace what you sweated out and did not drink.
You may sweat about 0.7 litres an hour in these conditions. If you drank nothing, that is about 1% of your body weight over this session.
Add some salt. A session this long or sweaty also loses salt, so water alone is not enough. Try nimbu pani with a pinch of salt and some sugar, coconut water, or ORS.
Water to drink during play, by weather and time
Litres for Badminton at "Regular play" effort and 70 kg. The row for your weather is highlighted.
| Weather | 30 min | 60 min | 90 min | 120 min |
|---|---|---|---|---|
| Cool (below 20°C) | 0.2 L | 0.3 L | 0.5 L | 0.6 L |
| Mild (20 to 27°C) | 0.2 L | 0.4 L | 0.6 L | 0.8 L |
| Hot (28 to 34°C) | 0.3 L | 0.5 L | 0.8 L | 1.0 L |
| Very hot or humid (35°C and above) | 0.3 L | 0.6 L | 0.9 L | 1.2 L |
Check it on your own body
- Look at your urine. Pale straw colour is good. Dark yellow means you need more.
- Weigh yourself before and after playing. Each kilogram you lose needs about 1.25 to 1.5 litres to replace. Losing more than about 2% of your weight means you drank too little.
- Know the signs of too little: strong thirst, headache, dizziness, cramps or feeling very tired. Stop, rest in the shade and drink.
- Do not overdo it. Drinking far more than you sweat, more than about 1 litre an hour for a long time, can be harmful. Drink to your plan and to thirst, no more.
This is an estimate for healthy adults, based on general sports-medicine guidance. People sweat very differently. If you feel faint, confused or sick during heat, stop and get help. If you have a heart or kidney condition, or a doctor has limited your fluids, follow your doctor's advice.
Questions people ask
How much water should I drink when playing sports?
It depends on your weight, how hard you work, how long you play and how hot it is. Enter those into the calculator for your own plan. As a rough guide, most people need about 0.4 to 1 litre an hour while playing, drunk in small amounts every 15 to 20 minutes.
How does the calculator work out my sweat?
It estimates your sweat rate from the sport's effort level (METs, the same ones the calories calculator uses), the temperature and your body size. Then it suggests drinking about 70 percent of that during play and never more than 1 litre an hour. This follows the general approach of the American College of Sports Medicine. It is an estimate, because sweat rates differ a lot between people.
How can I tell if I am drinking enough?
Check your urine: pale straw colour is good, dark yellow means drink more. If you can, weigh yourself before and after playing. Losing more than about 2 percent of your body weight means you did not drink enough. Each kilogram lost needs about 1.25 to 1.5 litres to replace.
Do I need electrolytes or a sports drink?
For play shorter than about an hour, water is usually enough. In long, hot or very sweaty sessions you also lose salt, so a drink with salt helps. Simple options are nimbu pani with a pinch of salt and some sugar, coconut water or ORS.
Can you drink too much water?
Yes. Drinking far more than you sweat, especially more than about 1 litre an hour for a long time, can dilute the salt in your blood, which is dangerous. Do not force yourself to drink more than the plan, and drink to thirst as well.
Is this medical advice?
No. It is general guidance for healthy adults who play sport. If you have a heart, kidney or other health condition, or a doctor has set a limit on how much you may drink, follow your doctor's advice instead.
