How to use this calculator
Compare formula-based estimates of resting energy expenditure using adult age, height, weight and the selected formula inputs. Energy is displayed in kilocalories per day.
How the estimate is calculated
Mifflin–St Jeor uses 10 × weight in kg + 6.25 × height in cm − 5 × age, with the selected sex coefficient. Harris–Benedict uses a different set of coefficients. Katch–McArdle and Cunningham use estimated lean body mass, derived from the entered body-fat percentage.
The calculator also displays an arithmetic average of the four equations and activity-multiplied estimates. This average is a tool convention, not a separate validated prediction equation. The 40/30/30 macro illustration is another fixed assumption.
What the estimate cannot tell you
These formulas estimate resting energy; they do not measure metabolism. An inaccurate body-fat input changes both lean-mass equations. Activity multipliers and macro illustrations are not individualized intake prescriptions. This adult tool is not intended to set nutrition targets for pregnancy, children or medical treatment.
Worked example
For the male coefficient, age 30, weight 70 kg and height 170 cm give a Mifflin–St Jeor estimate of 1,617.5 kcal/day. The other equations can give different values.