Hydration Schedule Calculator
Calculate how much water to drink each hour based on your body weight, activity duration and temperature. Includes a bar chart of hourly targets.
How to use this tool
- Enter body weight, hours of activity and temperature in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your target per hour and the full breakdown beneath it.
Adequate hydration supports performance, cognition and thermoregulation. General guidelines recommend 30–40 ml/kg/day at rest; hot conditions and activity increase needs further.
Not medical advice. Individual needs vary. Drink to thirst and consult a doctor if you have kidney or heart conditions.
Frequently asked questions
- Does temperature affect hydration needs?
- Yes — for every 5 °C above 20 °C this calculator adds 10% to the base requirement to account for sweat losses.
- Should I drink all at once or spread it out?
- Spread intake evenly throughout the day. Drinking too much at once can dilute blood sodium (hyponatremia) in extreme cases.