About TDEE Steps

TDEE Steps is a set of free energy-expenditure calculators that show their working. Instead of a single number, every calculator writes out the equation, substitutes your values and shows each intermediate result, so you can check the math yourself.

The equations

Mifflin-St Jeor (the main calculator): Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. “A new predictive equation for resting energy expenditure in healthy individuals.” American Journal of Clinical Nutrition, 1990;51(2):241-247.

Katch-McArdle (the body fat calculator): BMR = 370 + 21.6 × lean body mass in kg, as presented in Katch, Katch and McArdle’s exercise physiology texts.

Adaptive estimate (the adaptive calculator): works backwards from your own intake and weight change, treating one kilogram of body mass change as roughly 7,700 kcal. That figure is a widely used approximation, not an exact constant.

The activity multipliers (1.2, 1.375, 1.55, 1.725 and 1.9) are the most commonly published set used alongside these equations.

What these numbers are

Every result here is an estimate for the general population. Individual metabolism varies, and predictive equations carry real error for any one person. Treat the number as a starting point and adjust it from your own weight trend over a few weeks.

This site is for general information only and is not medical or nutritional advice. If you are pregnant, managing a medical condition, or have a history of disordered eating, talk to a qualified professional before changing what you eat.