Sweat Rates

Knowing your sweat rates is a start in mastering your hydration and fuelling strategy for training, racing or game day. You’ll understand how much fluid replacement is needed under varying conditions, so that you can perform at your best.

Adding the knowledge of your sodium concentration loss to your tool kit will help determine the electrolytes needing replacement when exercising. Therefore, knowing these two aspects puts you in a solid position to kick starting a robust hydration and fuelling strategy.

Ensure you have a proper warm up when you are going to engage in the activity that’s going to make you sweat it out.

The steps below will guide you on how to measure your sweat rate. Once you have completed the exercise and collated your data then input that data into the calculator below and the results will be calculated for you.

You can use the calculator below for any activity where you sweat whether it’s an intermittent or endurance activity.

Good luck!


Steps to measure your sweat rate

  1. Void all urine, then weigh-in wearing little to no clothing, in order to obtain the most accurate reading.
  2. Following the weigh-in, exercise for at least 45 mins up to 2 hours while keeping track of the quantity of fluid consumed.
  3. After exercise, dry yourself off, and step onto the scales again. Make sure to wear exactly what was worn when measuring your wright before you exercised.
  4. Subtract the post-exercise weight from the pre-exercise weight in kilograms or pounds and convert the difference to millilitres (1g = 1ml) or fluid ounces loss (1ml = 0.03 fl oz).
  5. Then add to that number the amount of fluid (ml/fl oz) that were consumed during the exercise. This will determine how much sweat was lost during exercise.
  6. Divide the total sweat loss by the total duration of the exercise to determine total fluid loss per hour of exercise.



Sweat Rate Calculator

Exercise duration minutes
Body weight at start of exercise kg or lbs
Body weight at end of exercise kg or lbs
Change in body weight kg or lbs
% Bodyweight change %
Drink bottle weight at start of exercise kg or lbs
Drink bottle weight at end of exercise kg or lbs
Drink consumed l or fl oz
Total sweat loss l or fl oz
Average sweat rate per 60 mins l/hr or fl oz/hr
Optional: If you have done your sodium concentration test then enter the details below.
Avg Sweat Sodium Concentration mg/l
Estimated sodium loss per 60 mins mg/hr
Estimated total sodium loss for this session mg