Free Calculator

Sweat Rate Calculator

Weigh yourself before and after a workout, note how much you drank. Get your personal sweat rate, fluid deficit, and race-day hydration target.

Weight unit

Pre-workout weight (kg)

Post-workout weight (kg)

Fluid consumed during workout (ml)

Workout duration (minutes)

Temperature (°C)

Exertion during the test

Sex

900

Sweat rate (ml/hr)

0.7%

Body weight lost

630–765

Race target (ml/hr)

810

Hot-day target (ml/hr)

405–810

Sodium (mg/hr)

moderate

Sweater category

Hyponatremia risk: low — Hydration mix looks balanced; keep monitoring with the in-race sip-not-gulp rule.

Race target is ~70–85% of sweat rate — replacing 100% is unnecessary and risks over-drinking. Deficit >2% body weight indicates meaningful dehydration (ACSM guideline).

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Your sweat rate is just the start.
Your full Neverwall plan calculates session-by-session fluid targets matched to your race distance, course conditions, and sweat profile.

Build my full plan — €19