Daily Water Intake Calculator

Discover exactly how much water you should drink every day to stay perfectly hydrated based on your body weight, exercise level, and climate.

Hydration Target
Enter your weight, daily exercise, and environment.
kg
minutes
Daily Water Target
2.96
Liters
Conversions
UnitDescriptionAmount
OuncesStandard imperial volume100 oz
MillilitersStandard metric volume2,963 ml
GlassesAssuming standard 8 oz (250 ml) cups~ 13 cups
Understanding Hydration

Hydration isn't just about quenching thirst. Your body is composed of about 60% water, and it relies on adequate hydration for joint lubrication, temperature regulation, cellular function, and flushing out waste.

How the math works

The old rule of "8 glasses a day" is an outdated oversimplification. Larger bodies require significantly more fluid than smaller bodies to maintain equilibrium.

  • The Baseline: The modern scientific baseline is to drink 0.5 ounces of water per pound of body weight (or about 33ml per kg).
  • The Exercise Modifier: When you sweat, you lose fluids rapidly. You must replenish this by adding roughly 12 ounces (350ml) for every 30 minutes of strenuous exercise.
  • The Climate Modifier: In hot or extremely humid environments, your passive sweat rate increases even while resting. We pad the calculation by 10% to 20% to account for this invisible loss.
Frequently Asked Questions