Hydration Needs Calculator

Estimate a practical daily fluid target based on body weight, temperature, activity level, and exercise duration.

Used as the base for your daily fluid estimate.
Warmer weather usually increases fluid needs.
More movement usually means more fluid loss.
Extra exercise adds extra fluid need.
People who sweat more often need more fluids.
Choose a simple or more detailed result.
How we calculate

We start with a simple body-weight fluid estimate, then add extra fluid based on temperature, activity level, sweat rate, and exercise duration.