Water Intake Calculator (How Much Water per Day)
Water intake calculator: how much water to drink per day from your body weight and exercise.
V = 33 mL × kg + 0.35 L × hexercise
How to use this calculator
- Choose the quantity you want under “Solve for”.
- Type the known values and pick their units: any combination works.
- The result updates as you type. Open “Show the steps” to see the substitution.
A common guideline is about 33 mL per kg of body weight, plus roughly 0.35 L for every hour of exercise.
Food provides about 20 % of daily water; needs rise in hot weather, illness, pregnancy and breastfeeding.
For general information only; it does not replace advice from a doctor or other health professional.
Formula
V = 33 mL × kg + 0.35 L × hexercise
| Symbol | Quantity | Units |
|---|---|---|
| m | Body weight | kg, g, mg, µg, t, lb, oz, st, US ton, ct, Da |
| t | Exercise per day | s, ms, µs, ns, min, h, d, wk, yr |
| V | Daily water | L, mL, µL, m³, dm³, cm³, gal, gal (UK), qt, pt, cup, fl oz, ft³, in³ |
Worked example
Given: m = 154.324 lb · t = 30 min
V = 0,033 L/kg · m + 0,35 L/h · t
Result: V = 84.0278 fl oz
Frequently asked questions
How much water for 70 kg and 30 min of exercise?
About 2.5 L, or 10 glasses.