Your Total Daily Energy Expenditure (TDEE) is the number of calories your body burns in a typical 24 hours, resting metabolism plus everything you do on top of it (walking, training, fidgeting, digesting food). It's the "maintenance" number: eat that many calories, and your weight stays roughly flat. Eat below it and you lose weight; eat above it and you gain.
This calculator uses the Mifflin-St Jeor equation in metric units (kg and cm), the most accurate widely-used BMR formula for healthy adults, then multiplies BMR by an activity factor to estimate TDEE. The output is your maintenance level, the anchor point you set deficits or surpluses against.
The activity multiplier is the biggest source of imprecision in any TDEE estimate. The standard factors (1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 extra active) are population averages, your real factor depends on job type, training volume, recovery, and especially non-exercise activity thermogenesis (NEAT), which can vary by 200-800 calories per day between individuals at the same nominal activity level. An office worker who walks at lunch and takes the stairs sits closer to 1.4; the same office worker who drives to a desk and sits all evening is closer to 1.2. Reality-check this number by tracking weight at consistent intake for 2-3 weeks; a flat scale at your eaten calorie level is your real TDEE, by definition.
Key takeaway
TDEE is a maintenance number, not a goal. Whether you want to lose weight, gain muscle, or hold steady, every plan is built around your TDEE: subtract for fat loss, add for muscle gain, or eat at it for maintenance. The activity multiplier matters more than people expect, a sedentary day vs. a moderately active day can shift TDEE by 400-500 calories at the same bodyweight.
How it's calculated
The Mifflin-St Jeor BMR equation (metric):
- Men:
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 - Women:
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
BMR is what you'd burn lying in bed all day. TDEE = BMR × activity factor, where the factor accounts for movement and exercise:
- 1.2 Sedentary, desk job, little or no exercise
- 1.375 Light, 1–3 light workouts/week
- 1.55 Moderate, 3–5 workouts/week
- 1.725 Active, 6–7 workouts/week or physical job
- 1.9 Very active, heavy training + physical labor
Most people overestimate their activity factor by one bracket. If your weight isn't moving the way the math says it should after 2-3 weeks, drop a level and recalculate.
Source: Mifflin-St Jeor equation
Examples
30-year-old man, 75 kg, 175 cm, moderate activity
- Sex Male
- Age 30 years
- Weight (kg) 75 kg
- Height (cm) 175 cm
- Activity level Moderate (3–5 days/week)
BMR works out to about 1,699 calories, roughly what a 30-year-old, 175 cm, 75 kg man burns at rest. With moderate training (3-5 days/week), TDEE rises to about 2,633. That's the maintenance number to set fat-loss or muscle-gain offsets against.
45-year-old woman, 65 kg, 165 cm, lightly active
- Sex Female
- Age 45 years
- Weight (kg) 65 kg
- Height (cm) 165 cm
- Activity level Light (1–3 days/week)
BMR ≈ 1,295 calories for a 45-year-old, 165 cm, 65 kg woman with light activity. TDEE comes in around 1,781, roughly the maintenance ceiling for someone with a desk job and 1-3 light workouts a week. Going much below that for sustained periods risks metabolic adaptation.
Frequently asked questions
How is TDEE different from BMR?
BMR (Basal Metabolic Rate) is the energy your body uses at rest just to stay alive, heart, lungs, organ function. TDEE (Total Daily Energy Expenditure) is BMR plus everything else: physical activity, the thermic effect of food (~10% of TDEE), and non-exercise activity like walking and fidgeting. BMR is the floor; TDEE is what you actually eat against day to day.
How accurate is the Mifflin-St Jeor TDEE estimate?
The Mifflin-St Jeor BMR formula is accurate to within ±10% for about 80% of healthy adults. The activity multiplier introduces additional uncertainty, self-reporting "moderate" activity is notoriously unreliable. Treat the TDEE output as a starting point. Track actual weight over 2-3 weeks; if the trend doesn't match expectations, adjust the activity level or the calorie intake by 100-200 calories and continue.
Should I use TDEE for weight loss or weight gain targets?
Yes, TDEE is the anchor. For fat loss, subtract a moderate deficit (300-500 calories/day for ~0.5-1 lb/week loss). For lean muscle gain, add 200-300 calories/day above TDEE. Avoid drastic cuts (>1,000 cal below TDEE) for long stretches: they tend to suppress BMR through metabolic adaptation, sacrifice muscle, and rebound when the diet ends.
Why does activity level matter so much?
Because the activity multiplier is applied to BMR, small bracket changes compound. A 1,700-calorie BMR at sedentary (1.2) gives 2,040 TDEE; at moderate (1.55) it's 2,635, a 595 calorie gap from the same person on a different schedule. Most people pick one bracket too high (e.g., marking a desk job + 4 weekly workouts as "active" when "moderate" is the right bin). When in doubt, pick the lower bracket and adjust based on weight trend.