BMR & TDEE Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) to find exactly how many calories your body needs each day. Essential for setting any calorie-based diet goal.
About this calculator
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to sustain vital functions — breathing, circulation, and cell repair. This calculator uses the Mifflin-St Jeor equation, the most validated formula for adults. For males: BMR = 88.362 + (13.397 × weight_kg) + (4.799 × height_cm) − (5.677 × age). For females: BMR = 447.593 + (9.247 × weight_kg) + (3.098 × height_cm) − (4.330 × age). TDEE is then computed as: TDEE = BMR × activity factor, where the activity factor ranges from 1.2 (sedentary) to 1.9 (very hard exercise/physical job). TDEE represents your true daily calorie need — eating at TDEE maintains weight, below it loses weight, and above it gains weight.
How to use
Example: a 30-year-old female, 140 lbs (63.5 kg), 65 inches tall (165.1 cm), moderately active (factor 1.55). Step 1 — BMR: 447.593 + (9.247 × 63.5) + (3.098 × 165.1) − (4.330 × 30) = 447.593 + 587.2 + 511.5 − 129.9 ≈ 1,416 kcal. Step 2 — TDEE: 1,416 × 1.55 ≈ 2,195 kcal/day. This means she needs roughly 2,195 kcal to maintain her current weight. To lose 1 lb/week, she would target approximately 1,695 kcal/day (a 500 kcal deficit).
Frequently asked questions
What is the difference between BMR and TDEE and which one should I use for dieting?
BMR is the calories your body burns doing absolutely nothing — it represents survival-level metabolism. TDEE adds the calories burned through all daily movement, exercise, and digestion on top of BMR. For practical diet planning, you should always use TDEE as your baseline, not BMR. Eating at BMR while living an active life would create a dangerously large deficit. TDEE gives you an accurate maintenance level from which to create a controlled, sustainable deficit or surplus.
How do I choose the right activity factor for my TDEE calculation?
The activity factor is the most subjective part of the TDEE calculation and is frequently overestimated. Sedentary (desk job, little exercise) = 1.2; lightly active (1–3 days/week exercise) = 1.375; moderately active (3–5 days/week) = 1.55; very active (hard training 6–7 days/week) = 1.725; extra active (physical labor plus training) = 1.9. Most gym-goers fall into the 1.375–1.55 range. If your results don't match expectations after two weeks, adjusting the factor by one level is a practical correction.
Why does my TDEE change as I lose weight and how often should I recalculate it?
TDEE decreases as you lose weight because a lighter body requires fewer calories to maintain itself — both BMR and the energy cost of movement go down. This is sometimes called metabolic adaptation. As a rule of thumb, recalculate your TDEE every 10–15 lbs of weight lost, or every 4–6 weeks whichever comes first. Failing to update your calorie target as you shrink is one of the most common reasons fat loss plateaus occur after an initial period of progress.