What is the difference between BMR and TDEE?

BMR is the energy you burn at complete rest; TDEE is BMR multiplied by an activity factor, so it includes all your daily movement and exercise. TDEE is the number you actually eat around.

How accurate is a calculated TDEE?

Equation-based TDEE is typically within about 10% of measured expenditure. Use it as a starting point and adjust calories based on how your weight actually trends over 2–3 weeks.

Should I eat back the calories I burn exercising?

If you used an activity multiplier to get TDEE, exercise is already included — don't add it again. If you used your BMR or sedentary TDEE, you can add part of measured workout calories, but tracker estimates run high, so add conservatively.

How to calculate your TDEE (and use it)

Total daily energy expenditure (TDEE) is the number of calories you burn in a day. It is the single most useful number for changing your weight, because eating below it loses fat and eating above it gains weight. Here is how to calculate it properly.

The answer first

TDEE is a two-step calculation. First estimate your basal metabolic rate (BMR) — the energy you’d burn lying in bed all day — then multiply it by an activity factor that scales it up for movement and training. Use the TDEE & BMR calculator to do both at once, or follow the steps below.

Step 1: estimate BMR with Mifflin-St Jeor

The Mifflin-St Jeor equation (1990) is the modern standard and is more accurate than the older Harris-Benedict formula for today’s populations:

BMR (men)   = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
BMR (women) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

For a 30-year-old man at 80 kg and 180 cm:

10 × 80 + 6.25 × 180 − 5 × 30 + 5
= 800 + 1125 − 150 + 5
= 1780 kcal/day

Step 2: multiply by your activity factor

Pick the activity level that matches a typical week and multiply your BMR by it.

Activity level	Multiplier	Typical week
Sedentary	1.2	Desk job, little exercise
Lightly active	1.375	Light exercise 1–3 days
Moderately active	1.55	Moderate exercise 3–5 days
Very active	1.725	Hard exercise 6–7 days
Extra active	1.9	Physical job or twice-daily training

Our 1780 kcal BMR at “moderately active” gives 1780 × 1.55 ≈ 2759 kcal/day. That is the maintenance estimate. See the full activity multipliers reference for details.

Step 3: set calories for your goal

Adjust TDEE based on whether you want to lose, maintain or gain:

Goal	Calories	Rough weekly change
Fat loss	TDEE − 15–20%	~0.4–0.7 kg loss
Maintain	TDEE	Stable
Lean gain	TDEE + 10–15%	~0.2–0.4 kg gain

A 500 kcal daily deficit is the classic target for about 0.45 kg (1 lb) of fat loss per week, though real results depend on adherence and water-weight noise.

Step 4: turn calories into macros

Once you have a calorie target, split it into protein, carbs and fat with the macro calculator. Keep protein high (1.6–2.2 g/kg) across every goal to protect or build muscle. For the reasoning, read how to set your macros by goal.

Why it’s only an estimate

These equations are population averages. Your real expenditure depends on body composition, genetics, non-exercise movement (fidgeting, walking) and how hard you actually train. The right way to use TDEE is as a starting point: eat at the estimate for 2–3 weeks, track your weight, and adjust by 100–200 kcal based on the trend.

If you want to understand why we use Mifflin-St Jeor over the alternative, read Mifflin-St Jeor vs Harris-Benedict.

A note on accuracy and health

The figures here are general fitness information, not medical or dietary advice. Very low calorie targets can be harmful; if you have a medical condition or are unsure, consult a qualified professional. See our methodology for the formulas behind every number.