Staying properly hydrated supports energy levels, digestion, and overall health. This free online water intake calculator estimates your ideal daily water intake in liters and glasses based on your body weight, daily exercise duration, and climate conditions. Simply enter your details below to get a personalized hydration target.
Estimate how much water you should drink daily based on your body weight, exercise, and climate.
How to Use the Water Intake Calculator
Enter your body weight in kilograms in the "Weight (kg)" field.
Enter how many minutes you exercise per day in the "Exercise Duration (minutes/day)" field (enter 0 if you don't exercise).
Select your climate from the "Climate" dropdown - choose "Normal" or "Hot / Humid".
Click "Calculate Water Intake" to see your recommended daily water intake in liters and glasses.
Frequently Asked Questions
The calculator starts with a base of about 33 ml of water per kg of body weight, then adds roughly 0.35 liters for every 30 minutes of daily exercise, plus an extra 0.5 liters if you select "Hot / Humid" climate.
Exercise causes you to lose fluids through sweat, so the more minutes you exercise, the more water the calculator adds to your daily total to help you stay hydrated.
If the weight field is empty or zero/negative, or the exercise duration is negative, the calculator displays "Please enter a valid weight and exercise duration" instead of a result.
Yes, this water intake calculator is completely free with no sign-up required, and you can use it as many times as you like.