What’s the difference between BMR and TDEE?

BMR (basal metabolic rate) is the energy your body uses just to stay alive at rest. TDEE (total daily energy expenditure) is BMR multiplied by an activity factor — everything you burn in a real day.

Which formula do you use to calculate TDEE?

The Mifflin-St Jeor equation for BMR, then an activity multiplier from 1.2 (mostly sitting) to 1.725 (very active). It’s the most accurate of the common predictive equations.

TDEE and BMR explained — and how we calculate yours

BMR is what you burn at rest; TDEE is what you burn in a full day. Here’s how the Mifflin-St Jeor equation works, what activity multipliers mean, and how to turn it into a daily target.

Every calorie target starts with one question: how much does your body burn in a day? Answer that, and a deficit is just "a bit less than this." Two numbers get you there — BMR and TDEE.

BMR: what you burn doing nothing

Your basal metabolic rate (BMR) is the energy your body spends just to stay alive — heartbeat, breathing, brain, organs, maintaining temperature — if you did nothing but lie still all day. For most people it's the largest single chunk of daily calorie burn.

The most accurate simple way to estimate it is 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

This is the exact formula our free calculator uses — no guesswork, no vanity numbers.

TDEE: what you burn in a real day

You don't lie still all day. You walk, work, cook, train. Total daily energy expenditure (TDEE) takes your BMR and multiplies it by an activity factor:

Activity level	Multiplier	Looks like
Mostly sitting	1.2	Desk job, little exercise
Lightly active	1.375	On your feet or 1–2 workouts a week
Active	1.55	Active job or 3–5 workouts a week
Very active	1.725	Hard training most days

TDEE = BMR × activity

The number your calorie target is built on

So a woman who is 70 kg, 165 cm and 35 with a desk job has a BMR of about 1,395 and a TDEE of about 1,674. Eat below that, and she's in a deficit.

From TDEE to your daily target

Once you know your TDEE, your target is simply TDEE minus a deficit. Pick the pace, and the maths follows — every kilogram of fat is about 7,700 calories, as we cover in how a deficit causes weight loss.

A predicted TDEE is a starting estimate, not gospel. Your real burn can sit a little above or below it. The honest move is to start at the estimate and adjust from how your weight actually trends over a few weeks.

That "adjust as you go" step is where a static calculator stops and a coach begins — recomputing your target every time you weigh in, so the number stays right as your body changes.

Quick answers

Don't have your height in centimetres or weight in kilograms? The calculator handles the conversion. And if you're not sure of your activity level, pick the lower one — it's the safer estimate, and you can always adjust.

Common questions

What’s the difference between BMR and TDEE?: BMR (basal metabolic rate) is the energy your body uses just to stay alive at rest. TDEE (total daily energy expenditure) is BMR multiplied by an activity factor — everything you burn in a real day.
Which formula do you use to calculate TDEE?: The Mifflin-St Jeor equation for BMR, then an activity multiplier from 1.2 (mostly sitting) to 1.725 (very active). It’s the most accurate of the common predictive equations.