Water Intake Calculator
Legendary Water Intake Calculator
Personalized hydration guidance that adapts to your body, activity, climate, and health details for smart daily intake planning.
First choose your body profile, activity level, climate, and daily habits. Then tap Generate hydration plan below to reveal your recommended intake, schedule, and tips.
Body & lifestyle details
About the Water Intake Calculator
How much water you need depends on your body size, activity, climate and health. This calculator builds a personalised daily hydration target and a simple hourly schedule so you can spread your water through the day.
How to use the Water Intake Calculator
- Enter your Age, Gender, Weight (kg) and Height (cm).
- Select your Activity level and the Climate where you live or work.
- Add your Caffeine cups per day and Exercise days per week, and mark Pregnancy or a Kidney condition if they apply.
- Press Generate hydration plan to see your daily total, how it splits by activity and climate, and an hourly schedule.
Formula and method
The base amount is about 35 ml × body weight in kg. It is then adjusted for activity level, hot or humid climate, caffeine intake and pregnancy. People with kidney or heart conditions should follow their doctor's fluid advice instead.
Worked example
A 70 kg adult starts at 70 × 35 = 2,450 ml (about 2.5 litres). A moderately active person in a warm climate may need a few hundred millilitres more.
Tips
- Pale yellow urine is a simple sign that you are well hydrated.
- Drink steadily through the day rather than large amounts at once.
- Food supplies roughly 20 percent of your water. Fruit and vegetables count.
- Increase intake during illness with fever, vomiting or diarrhoea.