Sweat Rate Calculator

How sweat rate is calculated

Sweat rate is estimated by weighing yourself immediately before and after a workout, then adding back any fluid you drank during the session (since that fluid offset some of the weight loss you'd otherwise have seen).

Knowing your sweat rate lets you plan a hydration strategy that roughly matches fluid losses, particularly useful for long training sessions or races in hot conditions where under- or over-hydrating both carry real risks.

Where these numbers come from

The formulas and default values in this calculator are based on:

• Standard pre/post exercise weight-based sweat rate protocol used in sports science and endurance coaching

These are planning estimates for training purposes. Check with a coach, trainer, or physician before starting a new program or maxing out.