Health · 5 min read

BMR vs TDEE: What's the Difference & Which Should You Use?

BMR is the energy your body burns at complete rest — keeping your heart, brain and organs running. TDEE is your total daily burn including movement and exercise. For weight goals, TDEE is the number that matters.

What each number means

• BMR (Basal Metabolic Rate): typically 1,200–1,500 kcal for women, 1,600–1,900 for men. Roughly 60–70% of everything you burn.
• TDEE (Total Daily Energy Expenditure): BMR × activity factor (1.2 sedentary → 1.9 very active). This is your true maintenance level.

Get both numbers in seconds with our calorie calculator — it computes BMR with the Mifflin-St Jeor equation, then applies your activity level.

Which to use for weight loss

Always set your calorie target from TDEE, not BMR. Eating at or below BMR is unnecessarily aggressive for most people — it ignores every calorie you burn moving. A sensible cut is TDEE minus 300–500 calories. Eating at TDEE maintains weight; above it, you gain.

Why your TDEE isn't fixed

Lose 10 kg and your TDEE can drop 150–300 kcal — smaller bodies burn less. Build muscle and it nudges up. Recalculate after every 5 kg change, and treat any calculator as a smart starting estimate to adjust against 2–3 weeks of real-world results.

Related: How many calories should I eat to lose weight?

How activity multipliers work

• Sedentary (×1.2): desk job, little to no exercise
• Lightly active (×1.375): light exercise or sports 1–3 days a week
• Moderately active (×1.55): moderate exercise 3–5 days a week
• Very active (×1.725): hard exercise 6–7 days a week
• Extra active (×1.9): physical job plus daily training, e.g. athletes and manual labourers

Most people overestimate which category they fall into — someone who works out three times a week but sits at a desk the rest of the time is usually "lightly" to "moderately" active overall, not "very active," since the multiplier accounts for your whole day, not just the workout itself.

Why metabolism isn't fixed

Both BMR and TDEE shift over time. Muscle burns more calories at rest than fat, so building muscle nudges BMR upward even without weight change. Conversely, prolonged, aggressive dieting can trigger "metabolic adaptation" — the body becoming more efficient and burning slightly fewer calories than the formula predicts, part of why weight loss often slows even when the numbers on paper say it shouldn't. This is normal and temporary, not a sign that the formulas are wrong; it's a reason to treat calculator output as a starting estimate to adjust from, not a fixed law.

Common mistakes when using BMR and TDEE

• Re-eating exercise calories on top of an already-active TDEE: if your activity level already accounts for your workouts, adding gym calories back in effectively double-counts them.
• Using someone else's numbers: BMR formulas are population averages; individual metabolisms can vary by 10–15% either side even at identical stats.
• Never recalculating: a TDEE calculated at the start of a diet becomes progressively less accurate as body weight changes.

BMR, TDEE and muscle gain

The same TDEE logic applies in reverse for muscle gain. Eating consistently above TDEE — typically by 200–300 calories for a controlled, mostly-muscle "lean bulk" — provides the energy surplus needed to build new tissue, paired with progressive resistance training. Eating far above TDEE (500+ calories) doesn't build muscle meaningfully faster; it mostly adds fat, since the body can only build muscle at a limited rate regardless of how much surplus energy is available. This is why aggressive "bulking" phases often do more harm to body composition than a patient, moderate surplus over a longer period.

Tracking TDEE accuracy over time

The most reliable way to find your real TDEE isn't a formula at all — it's tracking your actual food intake and weight change over 2–3 weeks. If your weight is stable while eating what you believe is your TDEE, that number is accurate for you specifically. If you're gaining or losing unexpectedly, adjust the target up or down by 100–150 calories and reassess. Formulas like Mifflin-St Jeor get most people within about 10% of their true number — close enough to start, but real-world tracking always has the final say.

Quick summary

BMR is your baseline; TDEE is your real daily target. Calculate both with our calorie calculator, set your goal (deficit to lose, surplus to gain, maintenance to hold steady) from TDEE, and revisit the number every few weeks as your weight and activity level change rather than treating a single calculation as fixed for months at a time.

Frequently asked questions