TDEE & BMR Calculator
Calculate BMR with Mifflin-St Jeor, Harris-Benedict or Katch-McArdle, then TDEE and calories to lose, maintain or gain.
🔒 Runs entirely in your browser — nothing is uploadedBMR formulas explained
Your basal metabolic rate (BMR) is the number of calories your body needs to keep you alive at rest: breathing, circulation, temperature control and cell repair. This calculator offers three well-known equations. The default, Mifflin-St Jeor, is 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men and the same with −161 instead of +5 for women.
The revised Harris-Benedict equation uses different coefficients: for men 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age, and for women 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age. The Katch-McArdle formula ignores age, height and sex and instead uses lean body mass: 370 + 21.6 × lean mass(kg), where lean mass is weight × (1 − body fat %). It suits people who know their body fat percentage reasonably well.
From BMR to TDEE and a calorie target
Total daily energy expenditure (TDEE) is BMR × activity factor. The factors used here are 1.2 for sedentary, 1.375 for light activity, 1.55 for moderate, 1.725 for very active and 1.9 for extra active. The result is the approximate number of calories you need to maintain your current weight. Eating about 500 kcal below it typically produces around half a kilogram (one pound) of loss per week, while eating about 500 kcal above it supports gradual gain. The calculator also shows milder 250 kcal steps, which are easier to sustain.
Using the results sensibly
All of these equations are population averages, so your actual needs can differ by a few hundred calories. Use the numbers as a starting point, weigh yourself under consistent conditions, and adjust every two to three weeks based on real progress. Very low intakes are not recommended without supervision. This page is for general information only and is not medical or nutritional advice; consult a doctor or registered dietitian before making major changes to your diet. All calculations happen locally in your browser and nothing is uploaded.
How to use
- Enter your detailsChoose metric or imperial units, then enter sex, age, height and weight.
- Pick a formulaUse Mifflin-St Jeor by default, revised Harris-Benedict, or Katch-McArdle if you know your body fat percentage.
- Select activity levelChoose the option that best matches your typical weekly exercise and daily movement.
- Read your caloriesSee your BMR, your TDEE, and daily calorie targets for losing, maintaining or gaining weight.