Health Tools

Sweat Rate Calculator

Estimate workout fluid loss and sweat rate per hour from body-weight change, workout duration, and fluid consumed.

Updated April 14, 2026
Free online tool
Planning and research use

Why this page exists

Hydration planning gets easier when pre- and post-workout weight, workout duration, and fluid intake turn into one hourly sweat estimate instead of a guess. This calculator helps visitors estimate fluid loss and sweat rate per hour from simple workout inputs.

Interactive tool

Run the estimate

Enter your numbers and read the result first, then use the sections below to understand what affects the outcome.

Calculator

Sweat rate calculator

Estimate workout fluid loss and sweat rate per hour from body-weight change, workout duration, and fluid consumed.

Result

1.15 L/hr

Estimated sweat rate per hour based on body-weight change, fluid consumed, optional urine loss, and workout duration.

Sweat rate per hour (L)1.15 L/hr

Estimated fluid loss (L)1.44 L

Sweat rate per hour (fl oz)38.8 fl oz/hr

Estimated fluid loss (fl oz)48.5 fl oz

The body-weight change plus fluid consumed points to about 1.44 liters of total fluid loss in this workout.
Spread across 1.25 hours, that works out to roughly 1.15 liters per hour.
Use the result as a practical hydration-planning estimate only, because sweat rate can change a lot with weather, pace, clothing, and measurement accuracy.

This is a practical hydration-planning estimate, not medical advice. Sweat rate can vary with weather, intensity, clothing, acclimation, and how accurately weights and fluid intake are measured.

Planning note

Last updated April 14, 2026. Use this tool to compare scenarios and plan ahead, then confirm important details with the lender, employer, insurer, contractor, or other qualified provider involved in the final decision.

How it works

What the calculator is doing

Choose imperial or metric units, then enter pre-workout weight, post-workout weight, workout duration, and fluid consumed.

Add optional urine loss if you want a slightly fuller fluid-balance estimate.

The calculator estimates total fluid loss and sweat rate per hour in practical units.

Understanding your result

This is a practical hydration-planning estimate, not medical advice. Sweat rate can vary a lot with weather, intensity, clothing, acclimation, and measurement accuracy.

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Examples

Ways people use this tool

Example scenarios help turn a quick estimate into a more useful comparison or planning step.

Check a long run or ride

A simple sweat-rate estimate can make it easier to plan fluid needs before the next similar workout.

Compare hot and cool conditions

Repeating the estimate after different sessions can show how much weather or intensity changes sweat loss.

Use it with hydration and recovery tools

Sweat-rate planning often fits naturally beside water-intake, calorie, and heart-rate-recovery tools.

FAQ

Common questions

How is sweat rate estimated here?

The calculator uses body-weight change plus fluid consumed, minus optional urine loss, to estimate total fluid loss and then divides that by workout duration.

Why use pre- and post-workout body weight?

Scale change is one of the simplest ways to estimate how much fluid the body lost during a session when it is combined with the fluids consumed during that workout.

Is this a medical hydration plan?

No. It is a simple planning estimate only, so use it as a starting point rather than a medical or performance prescription.

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Keep comparing

Use these related tools to compare nearby scenarios, check a second estimate, or keep narrowing down the right decision.

Health ToolsUpdated April 12, 2026