BMR vs TDEE: What's the Difference and Which Should You Use?
BMR is what your body burns at complete rest. TDEE adds everything else you do in a day. Here's how they're calculated, when each matters, and how to use them together for weight loss, maintenance, or muscle gain.
The one-line difference
- BMR (Basal Metabolic Rate) — the calories your body burns keeping you alive at complete rest.
- TDEE (Total Daily Energy Expenditure) — BMR plus everything else you do: fidgeting, walking, working out, digesting food.
TDEE is always higher than BMR. The gap between them is the calories you spend actually living your day.
How each is calculated
BMR is estimated from a regression equation. The most-used modern formula is Mifflin–St Jeor:
- Men: BMR = 10·weight(kg) + 6.25·height(cm) − 5·age + 5
- Women: BMR = 10·weight(kg) + 6.25·height(cm) − 5·age − 161
TDEE takes that BMR and multiplies by an activity factor:
| Lifestyle | Multiplier |
|---|---|
| Sedentary (desk job, no exercise) | 1.2 |
| Light (1–3 workouts/week) | 1.375 |
| Moderate (3–5 workouts/week) | 1.55 |
| Very active (6–7 workouts/week) | 1.725 |
| Athlete (2× daily training) | 1.9 |
So a 30-year-old woman, 165 cm, 65 kg, moderately active: BMR = 10·65 + 6.25·165 − 5·30 − 161 = 1,370 kcal TDEE = 1,370 × 1.55 ≈ 2,124 kcal
When to use BMR
- Setting a floor for calorie intake. Eating below BMR for long stretches is generally not recommended without medical supervision.
- Comparing metabolic rate between people of different sizes.
- Estimating a fasting baseline (e.g. for research or medical calculations).
When to use TDEE
- Weight loss: subtract 300–500 kcal from TDEE for a slow, sustainable deficit.
- Maintenance: eat at TDEE.
- Muscle gain: add 250–500 kcal above TDEE.
- Sports nutrition: planning fuel around training days vs rest days.
For any calorie-target decision, TDEE is the number you actually use. BMR is an input to TDEE, not a target on its own.
Worked example — same person, different goals
Same woman above, TDEE = 2,124 kcal:
| Goal | Daily target | Weekly change |
|---|---|---|
| Aggressive cut | 1,624 kcal | −1.0 lb |
| Moderate cut | 1,824 kcal | −0.6 lb |
| Maintenance | 2,124 kcal | 0 |
| Lean bulk | 2,374 kcal | +0.5 lb |
| Bulk | 2,624 kcal | +1.0 lb |
Comparison table
| Factor | BMR | TDEE |
|---|---|---|
| What it measures | Calories at complete rest | Calories over an entire real day |
| Depends on | Age, sex, height, weight | BMR × activity level |
| Typical value | 1,200–1,900 kcal | 1,600–3,500 kcal |
| Use case | Floor / baseline | Target intake for any body-comp goal |
| Changes with | Body composition, age | Also changes with training and job type |
FAQ
Is BMR the same as RMR? They're close but not identical. Resting Metabolic Rate is measured after light activity and includes small movement calories. RMR is usually ~10% higher than BMR.
Why do BMR/TDEE formulas disagree? They're regressions fit to different populations. Mifflin–St Jeor is the current default; Harris-Benedict is older and often over-estimates by ~5%. Katch-McArdle uses lean body mass instead of total weight, which is more accurate if you know your body-fat percentage.
Do I need to recalculate? Yes — as weight and activity change, so does TDEE. Recompute every 3–4 kg change or after a big lifestyle shift.
Try it
- BMR calculator — Mifflin–St Jeor with instant results.
- TDEE calculator — BMR × activity multiplier with all five levels.
Use them together: BMR sets your baseline; TDEE is what you eat around.