Katch-McArdle Formula

Jun 8 2021

Katch-McArdle Formula

The Katch-McArdle formula uses a different equation to calculate your BMR. It does not take sex into consideration, but readily adjusts to varying body types. If you know your lean body mass percentage (or your percentage of body fat), then you can apply this information to get a more accurate BMR.

For example, A 170 lb. person with 20% body fat would have 136 lbs. of lean muscle mass and 34 lbs. of fat.

  • [170 lbs. x 20% body fat = 34] , then [170 lbs. – 34= 136 lbs. of lean muscle mass]

Then calculate your BMR by using the following equation and multiplier.

370     +          [9.79759519   x   lean muscle mass] =       BMR
370     +          [9.79759519   x   136]                          =       1702.47295  

Once you have established your BMR using the Katch-McArdle formula, apply the same numbers used in the Harris-Benedict table to incorporate the amount of weekly physical exercise to get your TDEE.

Little to no exercise BMR x 1.2
Light exercise (1-3 times per week) BMR x 1.375
Moderate exercise (3-5 times per week) BMR x 1.55
Heavy exercise (6-7 times per week) BMR x 1.725
Extremely heavy exercise (more than 7 times per week + physical job) BMR x 1.9


Below are a few more ways for you to figure out just how many calories your body needs to maintain your current weight.

Harris-Benedict Formula
Resting Metabolic Rate
Mifflin-St Jeor Equation


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