BMR, RMR and TDEE: what they mean

BMR is the energy your body burns at complete rest; RMR is the same idea measured less strictly; TDEE is everything you burn in a day, including activity.

By the Calcist team · Updated October 26, 2026 · About a 3-minute read

The three terms

{_tbl(["Term", "What it means", "Used for"], [ ["BMR: basal metabolic rate", "Calories burned at complete rest, measured lying down after a night's sleep and a fast, in a comfortable room", "The base of most calorie estimates"], ["RMR: resting metabolic rate", "Calories burned at rest, measured under less strict conditions; usually a little higher than BMR", "Clinic and gym metabolic tests"], ["TDEE: total daily energy expenditure", "Everything burned in a day: resting metabolism, digesting food, exercise and everyday movement", "Setting a calorie target"]])}

How BMR is estimated

Most calculators use the Mifflin–St Jeor equation:

Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161

Example: a 35-year-old woman, 70 kg and 165 cm: 700 + 1,031.25 − 175 − 161 = 1,395 calories a day.

From BMR to TDEE

Multiply BMR by an activity factor, from about 1.2 (mostly sitting) to about 1.9 (very hard daily exercise or physical work). The woman above, lightly active at 1.375, has a TDEE of about 1,918 calories. Eating that much keeps weight roughly steady; eating less leads to weight loss over time.

Which number should I use?

Use TDEE for a daily calorie target. BMR alone is far below what an active person burns, so eating only your BMR is a much bigger deficit than it sounds.

Calculate yours

Use the BMR calculator, then the TDEE calculator, or set a goal with the calorie calculator.

Every worked example on this page was checked with Calcist's own engine and an independent reference.

Questions people ask

What does BMR mean?

Basal metabolic rate: the calories your body burns at complete rest to keep you alive, before any movement or digestion.

What is the difference between BMR and RMR?

Both measure calories burned at rest. BMR uses strict conditions (after sleep and a fast, lying down); RMR is measured less strictly and is usually slightly higher.

Is TDEE the same as maintenance calories?

Yes. TDEE is the total you burn in a day, so eating that amount keeps your weight about the same.

Should I eat my BMR to lose weight?

Usually not. BMR is well below what you burn in a normal day; a modest cut from your TDEE is the more common approach.