Your TDEE — Total Daily Energy Expenditure — is the number of calories your body burns in a full day. It is the single most useful number in nutrition: eat below it and you lose weight, eat above it and you gain. The calculator above estimates your TDEE from your stats and activity level, then shows calorie targets for fat loss, maintenance, and muscle gain.
What TDEE actually includes
TDEE has four components. The biggest is your basal metabolic rate (BMR) — the energy to keep you alive at rest (breathing, circulation, brain function), roughly 60–70% of the total. Then comes the thermic effect of food (digestion, ~10%), exercise activity (planned workouts), and NEAT — non-exercise activity like walking, fidgeting and standing, which varies enormously between people and is why two similar people can have very different TDEEs.
How TDEE is calculated
This calculator uses the Mifflin-St Jeor equation, the most validated BMR formula, then multiplies by an activity factor:
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Activity multipliers:
| Lifestyle | Multiplier |
|---|---|
| Sedentary (desk job, little exercise) | BMR × 1.2 |
| Light (light exercise 1–3 days/week) | BMR × 1.375 |
| Moderate (moderate exercise 3–5 days/week) | BMR × 1.55 |
| Active (hard exercise 6–7 days/week) | BMR × 1.725 |
| Very active (physical job + training) | BMR × 1.9 |
Using your TDEE for your goal
Fat loss: eat about 500 calories below TDEE per day. That pace — roughly 0.5 kg (1 lb) per week — preserves the most muscle. Don’t cut more aggressively without guidance.
Maintenance: eat at TDEE. Your weight should stay roughly stable week to week.
Muscle gain: eat roughly 300 calories above TDEE with enough protein (about 1.6–2.2 g per kg of body weight daily) and progressive training.
Track for two to three weeks and adjust: if weight isn’t moving as expected, shift intake by 100–200 calories. No formula beats your own data.
How accurate is it?
Mifflin-St Jeor predicts BMR within about 10% for most people, but individuals vary. Very muscular or very lean people, older adults, and anyone with a metabolic condition may sit outside the estimate. Treat the number as a starting point, then calibrate against the scale over a few weeks.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is what you’d burn lying in bed all day. TDEE adds everything else — digestion, daily movement and exercise — so it’s always higher and it’s the number that matters for eating.
Which activity level should I choose?
Be honest about an average week, not your best week. Most desk workers with 3–4 gym sessions land on “Moderate”. When in doubt, pick the lower option and adjust upward.
How many calories should I eat to lose weight?
Roughly 500 below your TDEE per day, which typically yields about 0.5 kg per week of fat loss. Keep protein high to protect muscle.
Does TDEE change as I lose weight?
Yes — a lighter body burns fewer calories, so your TDEE drops as you slim down. Recalculate every 5–10 kg lost to keep your deficit accurate.
Can I eat back exercise calories?
Fitness trackers often overestimate burn by 20–40%. If fat loss stalls, assume your tracker is optimistic and eat a little less rather than “eating back” the full amount.
Is the Mifflin-St Jeor equation the best one?
It’s the most validated for the general population. Alternatives like Harris-Benedict (older) and Katch-McArdle (needs body-fat %) exist, but Mifflin-St Jeor remains the standard recommendation.
References
BMR equation: Mifflin MD et al., American Journal of Clinical Nutrition (1990). Activity factors follow the standard Harris-Benedict activity classifications. Background: Basal metabolic rate — Wikipedia.