Sweat Rate Calculator
Estimate observed session sweat rate from body-mass change, measured drinks, urine and elapsed time.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Use comparable before and after body-mass measurements. Treat one kilogram of measured fluid as approximately one liter. Add drinks to body-mass loss and subtract urine. Divide the estimated volume by elapsed hours.
Estimated sweat (L)=mass before−mass after+drinks−urine; rate=volume/hours
Worked example
A change from 70 to 69.5 kg, drinking 0.5 L with no urine over one hour, estimates 1 L/h of sweat.
Assumptions and input details
An observed-session estimate, not a fluid-intake prescription or diagnosis. Food, respiratory losses, metabolic mass changes, wet clothing and measurement error can affect it. Inconsistent inputs giving negative estimated sweat are rejected.
References: Victoria Health: measuring sweat rate
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
The 19 mass definitions distinguish avoirdupois and troy measures, metric and regional measures. Japanese kin is 600 g; mainland Chinese shijin is 500 g.
The 36 volume definitions distinguish US liquid, US dry and Imperial measures. Cups carry an explicit definition. Japanese shō is 2401/1331 L and a gō is one tenth of it; the explicitly labelled 180 mL rice cup is separate.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · UK Imperial definitions · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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