About the Water Intake Calculator
Get a personal daily water estimate based on your body weight, how much you exercise and whether you live in a hot climate, in liters, glasses and fluid ounces.
Key features
- Daily water estimate from body weight
- Adjusts for exercise and hot weather
- Shown in liters, glasses and US fl oz
- kg or lb input
- Private: nothing leaves your browser
- Results update as you type
Stay well hydrated
Water supports temperature regulation, digestion, circulation and concentration. Needs vary with body size, activity and climate. This calculator gives a personalized daily starting point.
How it's estimated
Base = body weight (kg) × 0.033 L
Exercise = +0.35 L per 30 minutes
Hot climate = +0.5 L
Examples
| Person | Exercise | Climate | Daily water |
|---|---|---|---|
| 60 kg | None | Mild | ≈ 2.0 L |
| 70 kg | 30 min | Mild | ≈ 2.7 L |
| 70 kg | 60 min | Hot | ≈ 3.5 L |
| 90 kg | 45 min | Mild | ≈ 3.5 L |
Hydration tips
- Start the day with a glass of water.
- Carry a bottle and refill it regularly.
- Drink before, during and after exercise, and consider electrolytes for long or sweaty sessions.
- Eat water-rich foods such as cucumber, watermelon, oranges and soups.
General guidance only, not medical advice. People with kidney, heart or liver conditions, and those who are pregnant or breastfeeding, should follow their doctor's advice on fluid intake.
Related calculators
Plan your diet with the Calorie Calculator, or convert liters to ounces with the Volume Converter.
How to use the Water Intake Calculator
- Enter your numbers in the fields above. Units and options can be changed at any time.
- The result updates instantly as you type; there's no calculate button to press.
- Check the breakdown under the main result for the details behind the number.
- Adjust the inputs to compare scenarios, for example a different rate or term.