Water Intake Calculator

Estimate how much fluid you need each day.

Calculate water intake

Gender

About hydration

Why hydration matters

Water supports digestion, circulation, temperature regulation, joint lubrication and nutrient transport.

How this is calculated

Your baseline is derived from body weight, then adjusted for how active you are and the climate you spend your day in. Results are capped at four litres per day.

Where fluid comes from

Not all of it needs to be plain water. Above 2,800 ml a day, your result includes a suggested split between water, other drinks and fluid from food.

Fluid needs change with illness, medication and kidney health. Seek advice if you have a medical condition.