Three common formulas
Mifflin-St Jeor uses weight, height, age and a sex coefficient, and is the default in One Fitness Hub. Revised Harris-Benedict is another population equation. Katch-McArdle uses estimated lean mass, so it needs a body fat percentage; the BMR calculator falls back to Mifflin-St Jeor, with a visible note, when that field is blank. The app can also average the available formulas.
A worked example
A 35-year-old woman who weighs 77.1107 kg and is 167.64 cm tall has an estimated BMR of 1,483 kcal a day by Mifflin-St Jeor. That is the example on the BMR calculator.
BMR is not a food target
BMR describes resting energy only. Daily movement, digestion and exercise add to it, which is what TDEE estimates. No formula measures your own metabolism, and a body fat percentage is itself an estimate.
Who the estimate is for
These are fitness estimates for adults 18 and over, not medical or dietary advice. A doctor or dietitian can advise on individual energy needs.
Where BMR fits in your numbers
BMR is the first step of a longer chain: BMR, then an activity factor to reach TDEE, then a calorie level and a macro split. A change in the BMR formula moves everything after it by a similar proportion, which is why it is worth choosing a formula once and judging the results over weeks instead of switching to chase a number.
In One Fitness Hub
- The BMR calculator takes your measurements, lets you pick the formula and shows the result without an account.
- In Nutrition setup you choose the BMR formula: Mifflin-St Jeor (the default), Revised Harris-Benedict, Katch-McArdle with a recent body fat percentage, or the average.
- Targets are shown for adults 18 and over and are labelled estimates.
Common questions
Is BMR the same as TDEE?
No. BMR estimates energy used at rest. TDEE estimates a whole day, including activity.
Which BMR formula should I choose?
Mifflin-St Jeor is the default. Harris-Benedict is another population estimate. Katch-McArdle needs a useful body fat estimate. None measures your metabolism.
Does BMR change?
The formulas take weight, age and, for Katch-McArdle, body composition, so the estimate changes when those do.
Related terms
- TDEE: TDEE, or total daily energy expenditure, is an estimate of all the calories you use in a day, including resting energy and activity.
- Macros: Macros, short for macronutrients, are the three nutrients that provide calories: protein, carbohydrate and fat.
Keep reading
General education and fitness estimates, not medical or dietary advice. Figures from the app are informational and are not reviewed by a certified personal trainer.