Sweat Rate
Hydration Replacement
Estimate hourly sweat loss from a pre/post weigh-in and get a personal hydration replacement target.
Sweat Rate Calculator
Estimate your hourly sweat loss and personal hydration replacement target from a pre/post exercise weigh-in.
How the Calculator Works
Enter your pre-exercise weight, post-exercise weight, fluid consumed during exercise, and exercise duration. The calculator determines your sweat rate, total fluid loss, dehydration percentage, and recommended replacement rate.
Dehydration Thresholds
<1% body weight loss: well hydrated. 1-2%: mild dehydration, early performance decline. 2-4%: moderate dehydration, significant impairment. >4%: severe dehydration, risk of heat illness. Aim to stay under 2% loss during exercise.
Dehydration Effects
Medical Disclaimer
This calculator provides estimates based on weight change. It does not account for respiratory water loss, metabolic water production, or bladder contents. For precise measurement, repeat the test multiple times in similar conditions.