Science-backed metrics for body composition and energy expenditure.
BMI, BMR, TDEE, body fat percentage, ideal weight — five metrics that show up in every diet, fitness, and health plan. Each calculator here cites its underlying formula (Mifflin-St Jeor for BMR, Devine for ideal weight, Jackson-Pollock for body fat) and runs entirely in your browser. The numbers are starting points, not prescriptions; pair them with professional guidance for clinical decisions. No inputs are uploaded or logged.
Calculate Body Mass Index from height and weight. Shows WHO classification. 100% in-browser.
Estimate Basal Metabolic Rate using the Mifflin-St Jeor equation. Calories you burn at rest.
Estimate Total Daily Energy Expenditure from BMR and activity level. Plus maintenance and calorie-target suggestions.
Compare four published methods — Hamwi, Devine, Robinson, Miller — side by side.
Estimate body fat % using the US Navy (Hodgdon-Beckett) circumference method.
BMI is a height/weight ratio. Athletes with high muscle mass score 'overweight' on BMI but lean on body fat. Use both.
Within 10-15% for most people. Activity factor is the biggest source of error — pick honestly.