Cunningham Equation Calculator

The Cunningham equation can be used to calculate your resting metabolic rate (RMR; the calories you burn while you're at complete rest). The Cunningham equation has been found to yield acceptable estimates in muscular physique athletes [1].

The Cunningham equation is as follows:

RMR = 22 * FFM + 500

You can use the calculator below to calculate your RMR using the Cunningham equation.

Your RMR: 0 kcal

Apply physical activity factor

To get a good idea of how much calories are burnt in total, you should also factor in the so-called physical activity factor (PAF). The RMR is multiplied with the PAF to obtain the total amount of calories that is burnt in a day.

Total energy expenditure: 0 kcal

Physical activity factor (PAF) table

You can refer to the table below for an indication of your physical activity factor (PAF). Adapted from Clark et al. [2].

Category Description Physical activity factor (PAF)
Very light Seated and standing activities, office work, driving, cooking; no vigorous activity 1.2–1.3
Low active In addition to the activities of a sedentary lifestyle, 30 minutes of moderate activity equivalent to walking 3 km in 30 minutes; most office workers with additional planned exercise routines 1.5–1.6
Active In addition to the activities of a low active lifestyle, an additional 3 hours of activity such as bicycling 16–19 km an hour, walking 7 km an hour 1.6–1.7
Heavy Planned vigorous activities, physical labor, full-time athletes, hard-labor professions such as steel or road workers 1.9–2.1


  1. Tinsley, Grant M., Austin J. Graybeal, and M. Lane Moore. "Resting metabolic rate in muscular physique athletes: validity of existing methods and development of new prediction equations." Applied Physiology, Nutrition, and Metabolism 44.4 (2019): 397-406.
  2. M. A. Clark, S. Lucett, R. J. Corn, et al. NASM essentials of personal fitness training. 4th ed. Lippincott Williams & Wilkins, 2011.