BMR Calculator
with Basal Metabolic Rate Estimate

What BMR means

Basal Metabolic Rate, usually shortened to BMR, is an estimate of how many calories your body uses at complete rest to maintain basic functions such as breathing, circulation, and cell activity. It is a resting energy estimate, not a full daily calorie target.

This is why BMR is often used as a foundation in nutrition and fitness calculators. It provides a baseline, and then other tools such as TDEE calculators build on top of it to estimate real daily calorie needs once movement and exercise are included.

Mifflin-St Jeor formula

BMR vs TDEE

BMR reflects the calories your body would burn at rest. TDEE, which stands for Total Daily Energy Expenditure, is broader. TDEE includes your resting burn plus daily movement, exercise, and other activity.

That means your TDEE is usually higher than your BMR. For most people, BMR is the starting point, and TDEE is the next step when trying to estimate maintenance calories or build calorie targets for weight change goals.

Typical relationship

Why formulas differ

BMR formulas are estimates built from real-world datasets, but each formula uses a different statistical model and source population. That is why Mifflin-St Jeor and Harris-Benedict may not return the exact same number for the same person.

This does not mean one result is automatically wrong. It means the number should be understood as an estimate range rather than a perfectly precise measurement of metabolism. Real energy needs can also vary with body composition, hormone status, and daily routine.

Frequently Asked Questions