Free Hydration Calculator

Calculate your recommended daily water intake based on weight and activity level using the metric formula.

lbs

Daily Water (liters)

2.54 L

Daily Water (ounces)86 oz
Daily Water (cups)10.8 cups

Daily Water (liters) vs Body Weight

Weight-Based Hydration Formula

Base Water (liters) = Weight (kg) x 0.033

Adjusted Water = Base x Activity Multiplier

This formula is the standard metric approach. Active individuals need 20-60% more water than sedentary ones.

Example Calculation

A 170 lb moderately active person.

  1. 01Weight in kg = 170 x 0.4536 = 77.1 kg
  2. 02Base water = 77.1 x 0.033 = 2.54 liters
  3. 03Adjusted = 2.54 x 1.4 = 3.56 liters
  4. 04In ounces = 3.56 x 33.814 = 120 oz

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