Meet the Sweat Rate Calculator
Weigh yourself before and after a workout, enter what you drank and how long you trained, and get your sweat rate in litres per hour.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Illustration. Open the tool for the real thing.
What is the Sweat Rate Calculator?
Weigh yourself before and after a workout, enter what you drank and how long you trained, and get your sweat rate in litres per hour, percent body weight lost and a drinking target per hour.
It helps you avoid both dehydration and over-drinking.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
From your weights.
Under 2% is good.
Per hour and per 15 minutes.
AZRS tools are free to open and use.
It opens in your browser, so there is nothing to download.
Used for
Pick one to see how it fits.
How it compares
A plain look at this tool next to the usual alternative.
| This fitness tool | Desktop software | |
|---|---|---|
| Install | Nothing to install | Usually an app or program to install |
| Account | No signup | Depends on the product |
| Cost | Free to use | Free or paid, depends on the product |
| Where it runs | In your browser tab | On your computer |
Questions people ask
How often should I test?
Once in cool and once in hot conditions.
Is it free and private?
Yes: free, no signup, processed in your browser. How much you sweat per hour and how much to drink. Your own device keeps whatever is saved. How it works: Weigh yourself before and after, dry. Enter fluids and time.
Should I replace everything I sweat out?
Not necessarily. The tool gives a drinking target as a guide; many people drink to thirst. Ask a sports dietitian if you have a medical condition.
How do I use the Sweat Rate Calculator?
1. Weigh yourself before and after, dry. 2. Enter fluids and time. 3. Read your sweat rate and targets.
Any tips for good results?
Test in conditions like your race. Dry off sweat and use the toilet before the second weigh-in so the scale only shows sweat loss. Repeat the test in both cool and hot weather, since your rate changes with the temperature.
More free tools
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Try the Sweat Rate Calculator now
How much you sweat per hour and how much to drink. Free to use.
Try it free