How to Use the BMR Calculator
Your basal metabolic rate (BMR) is the minimum number of calories your body burns just to keep your heart beating, maintain body temperature, and keep you breathing — even if you did nothing but lie in bed all day. This calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate formula in nutrition science, to calculate your BMR from height, weight, age, and sex, then multiplies it by your activity level to show your total daily energy expenditure (TDEE).
When planning a diet, it's safest to eat a modest amount below your TDEE rather than cutting drastically below your BMR — extreme restriction tends to burn muscle first, lowers your BMR over time, and can make weight regain worse afterward. If you want to build muscle instead, eating slightly above your TDEE while strength training is more effective. When choosing your activity level, factor in your job (desk work vs. physical labor) as well as your exercise routine.
Check the FAQ below for the difference between BMR and TDEE and tips for dieting safely. This result is not a medical diagnosis — it's a reference figure based on a standard formula that can vary by individual health status, so consult a professional for a personalized weight plan if needed.
Frequently Asked Questions
It's the minimum calories your body burns just to stay alive if you did nothing but lie down all day. Multiplying it by an activity factor gives your total daily energy expenditure (TDEE).
It's not recommended. Eating below your BMR can cause muscle loss, weight regain, and a slower metabolism. This result is a reference figure — consult a professional for a weight plan if needed.