Fitness calculators

Quick numbers for training. Everything is worked out in your browser, and nothing you type is sent anywhere. Every calculator works in lb and inches or kg and cm.

For calories and macros, use the calorie and macro calculator on eatgood.now.

Body fat calculator (US Navy method)Estimate your body fat percentage with a tape measure, using the US Navy formula, and compare it with healthy ranges for your age and sex. Works in lb or kg.
FFMI calculator (fat-free mass index)Work out your fat-free mass index (FFMI) and normalized FFMI from your height, weight and body fat. A BMI that counts only muscle, bone and organs.
One-rep max calculator (1RM)Estimate your one-rep max from a set of 1–12 reps, without testing it. Uses the Epley and Brzycki formulas, with a percentage chart for your working sets.
Barbell plate calculatorType the weight you want on the bar and see exactly which plates go on each side. Works with lb or kg plates, standard or lighter bars, and the plates your gym has.
Heart rate zone calculatorFind your moderate and vigorous heart rate zones for cardio from your age, using the American Heart Association method, with the Tanaka formula as a check.