How it works
Total Daily Energy Expenditure (TDEE) is the calories your body burns in a full day — resting metabolism plus movement, digestion and exercise. This calculator estimates Basal Metabolic Rate (BMR) with the Mifflin-St Jeor equation (Mifflin et al., *Am J Clin Nutr*, 1990), then multiplies by an activity factor. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women the constant is −161 instead of +5. TDEE = BMR × activity multiplier: sedentary 1.2, light 1.375, moderate 1.55, active 1.725, very active 1.9. Worked example on the defaults — male, 30 years, 80 kg, 178 cm, moderate activity. BMR = 10×80 + 6.25×178 − 5×30 + 5 = 800 + 1,112.5 − 150 + 5 = 1,767.5 → 1,768 kcal. TDEE = 1,768 × 1.55 = 2,739.63 → 2,740 kcal. Mild deficit (250 kcal below maintenance) = 2,490 kcal; mild surplus = 2,990 kcal. The CDC notes that roughly 3,500 kcal above or below maintenance over time correlates with about one pound of body-weight change, so 250 kcal/day targets roughly half a pound per week — slow enough to preserve lean mass when protein is adequate. TDEE is an estimate: thyroid status, genetics, NEAT (non-exercise activity like fidgeting and steps) and diet history shift real expenditure. Track weight for two to three weeks at calculated maintenance and adjust ±100–200 kcal based on scale trend rather than trusting the formula alone.
Formula
BMR (male) = 10×kg + 6.25×cm − 5×age + 5
BMR (female) = 10×kg + 6.25×cm − 5×age − 161
TDEE = BMR × activity factor
sedentary 1.2 · light 1.375 · moderate 1.55 · active 1.725 · very 1.9
Mild loss = TDEE − 250 · Mild gain = TDEE + 250
Worked example — defaults
Male · 30 yr · 80 kg · 178 cm · moderate
BMR = 1,768 kcal
TDEE = 2,740 kcal
Mild loss = 2,490 · Mild gain = 2,990 kcal/day
Tips
- Pick the activity level that matches an average week, not your best training week.
- If weight drifts despite hitting TDEE, adjust by 100–150 kcal every two weeks based on scale trend.
- Protein at 1.6–2.2 g/kg preserves muscle on a cut — pair with protein calculator.
- Very active multipliers overstate calories for many desk workers who train hard but sit otherwise.
- Eat at 2,740 kcal on the defaults to maintain; 2,490 for slow loss; 2,990 for slow gain.
Frequently asked questions
- What is TDEE?
- Total Daily Energy Expenditure — all calories burned in 24 hours including BMR, activity and the thermic effect of food. Eating at TDEE maintains weight; below loses; above gains. On the defaults TDEE is **2,740 kcal**.
- How accurate is Mifflin-St Jeor?
- Meta-analyses favour it over older Harris-Benedict formulas for estimating BMR — typically within roughly ±10% for most adults. Individual variation means you should verify against two to three weeks of scale data at **2,740 kcal** before committing to a large deficit.
- What are the default results for an 80 kg man?
- At **30 years**, **178 cm**, moderate activity: BMR **1,768 kcal**, TDEE **2,740 kcal**. Mild cut **2,490 kcal**; mild bulk **2,990 kcal**/day.
- How many calories to lose 0.5 kg per week?
- About **500 kcal/day** below TDEE (3,500 kcal ≈ 0.5 kg fat). The mild-loss line (**−250 kcal** → **2,490 kcal** on defaults) targets ~0.25 kg/week — slower but easier to sustain.
- Why is my BMR 1,768 but I eat more and stay lean?
- NEAT — steps, fidgeting, standing — can add hundreds of calories beyond the activity multiplier. If weight is stable above **2,740 kcal**, your real TDEE is higher; adjust upward rather than forcing the formula number.