TDEE Calculator
Free TDEE and BMR calculator using the Mifflin-St Jeor formula. Get maintenance calories, cut targets, and bulk targets for any goal in kg or lb.
Total Daily Energy Expenditure (TDEE) is the single most important number for anyone trying to gain muscle, lose fat, or hold steady — it’s the calorie level at which your body neither gains nor loses weight, and every nutrition target you set is a deviation from it. Cut 500 calories below TDEE and you’ll lose roughly a pound a week. Add 200 and you’ll gain slowly enough to actually build muscle without excess fat.
This calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then applies a research-backed activity multiplier to project your TDEE. It’s the same math MuscleBuddy uses internally to set your starting macros — the difference is the app then auto-adjusts your calories every week based on your actual weigh-in trend, so you’re not stuck guessing whether the formula is off by a few hundred kcal.
How this works
BMR is the energy you burn while completely at rest — keeping your brain running, heart beating, and organs functioning. The Mifflin-St Jeor formula, published in 1990, estimates BMR from weight, height, age, and biological sex:
BMR (male) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
BMR (female) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
TDEE = BMR × activity factor. Activity factors range from 1.2 (sedentary office worker) to 2.0 (athlete or manual laborer). The most common mistake is overestimating activity — 4–5 sessions of weight training per week is "moderate" (1.55), not "very active" (1.9). The latter is reserved for two-a-day athletes or people whose jobs are physically demanding.
For weight goals, the standard rule of thumb is roughly 3,500 kcal per pound of body fat (about 7,700 kcal per kilogram). A 500 kcal daily deficit projects to about a pound of weekly fat loss; a 250–300 kcal surplus supports lean gains without excess fat.
Mifflin-St Jeor has a measurement-validated accuracy of about ±10% in healthy adults. The right move is to treat the calculator output as a starting point, eat at that level for 2–3 weeks, then adjust based on what the scale actually does. MuscleBuddy automates this recalibration so you don’t have to re-run the numbers manually.
Frequently asked questions
- What is TDEE?
- Total Daily Energy Expenditure is the number of calories you burn in a day from all sources — your basal metabolism, the food you digest, the exercise you do, and your non-exercise movement.
- What is BMR and how is it different from TDEE?
- BMR is Basal Metabolic Rate — the calories your body burns at complete rest. TDEE is BMR multiplied by an activity factor (1.2 to 2.0 depending on lifestyle) to account for daily movement.
- Which BMR formula does this calculator use?
- Mifflin-St Jeor (1990), which is the most accurate published equation for general population estimation. It outperforms the older Harris-Benedict formula by 3–7% in validation studies.
- How accurate is a TDEE estimate?
- Mifflin-St Jeor is accurate within roughly ±10% for healthy adults. The biggest source of error is activity-multiplier choice — most people overestimate. Treat the number as a starting target and adjust based on weigh-in trends.
- Should I cut 500 calories below TDEE to lose a pound a week?
- A 500-calorie daily deficit roughly equates to 1 lb (0.45 kg) of fat loss per week, but real-world fat loss is non-linear because metabolic rate adapts downward. Plan to recalculate every 4 weeks.
- Why is my weight not moving even though I’m eating at TDEE?
- TDEE estimates have a ±10% margin and you may be off by a few hundred calories. If your weight is climbing on maintenance, drop calories by 100–150 and reassess after 2 weigh-ins.
- Do men and women calculate TDEE differently?
- The Mifflin-St Jeor formula differs by sex — men add 5 to the BMR result, women subtract 161 — to account for systematic differences in lean mass and metabolic rate.
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