TDEE Calculator - Total Daily Energy Expenditure

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest - keeping your heart beating, lungs breathing, and cells functioning. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor that accounts for all movement throughout the day: exercise, walking, fidgeting, and daily tasks. TDEE is what you actually burn; BMR is the floor. Eating at TDEE maintains your weight.

The Mifflin-St Jeor equation (1990) is the most widely validated formula for calculating BMR in the general population, with an average error of ±10% versus measured metabolic rate. Harris-Benedict (revised 1984) is slightly less accurate on average but remains widely used. The Katch-McArdle formula is most accurate for lean athletes who know their body fat percentage. This calculator provides both Mifflin-St Jeor and Harris-Benedict.

For safe, sustainable fat loss, eat 250–500 kcal below your TDEE. A 500 kcal/day deficit produces roughly 0.5 kg/week of fat loss (since 1 kg of fat ≈ 7,700 kcal ÷ 7 days = 1,100 kcal/day for 1 kg/week; half that for 0.5 kg). Deficits larger than 750–1,000 kcal/day increase muscle loss risk and are difficult to sustain. Never eat below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision.

Sedentary (1.2×): desk job, no formal exercise. Lightly Active (1.375×): office work plus 1–3 days of gym or light cardio per week. Moderately Active (1.55×): physically active work or 3–5 days of gym per week at moderate intensity. Very Active (1.725×): hard training 6–7 days/week or physically demanding job. Extra Active (1.9×): hard daily exercise plus physical labor job, or twice-daily training. Most gym-goers fall into Lightly or Moderately Active.

TDEE calculators estimate within ±10–20% for most adults. Individual variation in metabolism, gut microbiome, NEAT (non-exercise activity thermogenesis), and body composition creates a range around the formula. The estimate is a starting point - track your weight weekly for 2–3 weeks at the calculated intake and adjust up or down by 100–200 kcal if results don't match expectations.

Recalculate TDEE every 4–6 weeks or after every 3–5 kg of weight change. As weight decreases, BMR falls (less body mass to maintain), so your calorie target needs to drop slightly to maintain the same deficit. Athletes increasing training load should recalculate activity level upward. Missing this adjustment is the most common reason weight loss 'stalls' - the target becomes maintenance rather than a deficit.

Yes, indirectly. TDEE activity multipliers include a small factor for the thermic effect of food (TEF) - the energy used to digest and process nutrients. TEF contributes roughly 10% of total daily expenditure: protein digestion burns the most (20–30% of protein calories), followed by carbohydrates (5–10%), and fat (0–3%). Higher-protein diets therefore have a slight metabolic advantage beyond satiety.

Natural muscle gain requires a calorie surplus above TDEE. A moderate surplus of 250–500 kcal/day ('lean bulk') produces roughly 0.1–0.25 kg of lean mass per week for most people, with minimal fat gain. Larger surpluses (500+ kcal) speed up weight gain but increase fat accumulation proportionally. High protein intake (1.6–2.2 g/kg body weight) is essential regardless of surplus size.

For women, the Mifflin-St Jeor BMR formula is: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161. TDEE is then BMR × activity factor. For example, a 30-year-old woman weighing 65 kg and 165 cm tall has a BMR of about 1,454 kcal. At a Moderately Active level (×1.55), her TDEE is approximately 2,253 kcal/day.

Standard TDEE formulas (Mifflin-St Jeor, Harris-Benedict) are validated for adults aged 18+. They underestimate calorie needs for growing children and teenagers because growing bodies have additional energy demands beyond maintenance. For children and teens, pediatric growth charts and age-specific guidelines from organisations like the Academy of Nutrition and Dietetics are more appropriate. Always consult a healthcare provider for youth nutrition planning.

Several factors can produce a higher-than-expected TDEE: high muscle mass (muscle burns more calories at rest than fat), younger age (metabolism is higher), male gender (higher lean body mass on average), or an activity level that is genuinely higher than you realize - NEAT from fidgeting, walking, and standing can add 300–700 kcal daily without formal exercise. Conversely, if your actual weight gain/loss doesn't match the formula, track food accurately for 2 weeks; most 'high metabolism' cases turn out to be consistent underreporting of food intake.

Yes - your TDEE is your maintenance calorie intake, the number of calories at which your body weight stays stable over time. Eating consistently below TDEE creates a deficit (weight loss); eating consistently above creates a surplus (weight gain). For practical purposes, use your TDEE as your baseline and adjust upward or downward based on your specific goal: typically ±250 to ±500 kcal for fat loss or lean muscle gain.