Find your Total Daily Energy Expenditure (TDEE) based on age, weight, height, and activity level.
Ages 15–100
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any health-related decisions or starting any diet or exercise programme.
🎯 Pro Tip
Most people overestimate their activity level. If unsure, choose one level lower than you think — it's better to underestimate and adjust than to eat too many calories.
Mifflin-St Jeor Equation (recommended):
Male: BMR = 10×W + 6.25×H − 5×A + 5
Female: BMR = 10×W + 6.25×H − 5×A − 161
Where W = weight (kg), H = height (cm), A = age (years)
Activity Multipliers (Harris-Benedict):
Sedentary: BMR × 1.2 | Light: BMR × 1.375 | Moderate: BMR × 1.55
Very Active: BMR × 1.725 | Super Active: BMR × 1.9
Did you know?
When you read "200 Calories" on a food label, those are actually kilocalories (kcal) — 1 food Calorie = 1,000 scientific calories. So a cheeseburger at 500 Cal contains 500,000 small calories!
The calorie was first proposed by French physicist Nicolas Clément in 1819, but its application to nutrition began in the 1880s when American chemist Wilbur Atwater built the first human respiration calorimeter. He painstakingly measured the caloric content of hundreds of foods, establishing the 4-4-9 rule (protein & carbs = 4 cal/g, fat = 9 cal/g) still used on nutrition labels today. The Mifflin-St Jeor equation revolutionized individual calorie estimation when published in the American Journal of Clinical Nutrition in 1990 — replacing the 1919 Harris-Benedict equation that had been the gold standard for 71 years. A 2005 study by the American Dietetic Association found Mifflin-St Jeor to be accurate within 10% for 82% of the population.
Your body is only about 20–25% efficient at converting food energy into mechanical work — meaning most of what you eat powers your internal chemistry, not your muscles.
The "3,500 calories = 1 lb of fat" rule was proposed by physician Max Wishnofsky in a 1958 paper and has since been refined — actual fat loss is more complex and non-linear.
Your brain uses roughly 20% of your BMR (about 400–500 calories/day) despite weighing only 1.4 kg — making it the most metabolically expensive organ per gram.
Digesting food itself burns calories: protein requires 20–30% of its calories just to be processed (Thermic Effect of Food), making it highly satiating.
Extreme calorie restriction triggers "metabolic adaptation" — your body can lower TDEE by up to 15% to conserve energy, a survival mechanism that makes prolonged dieting harder.
Elite Tour de France cyclists burn up to 9,000 calories per stage — roughly 4× a normal person's TDEE.
Total Daily Energy Expenditure (TDEE) is the total calories your body burns in a day, including exercise and daily movement. Eating at your TDEE maintains your current weight. Eat less → lose weight; eat more → gain weight.
A deficit of 500 calories/day leads to ~0.45 kg (1 lb) of fat loss per week — a safe, sustainable pace. A 1,000 cal deficit targets ~1 kg/week, which is the recommended maximum for most people. Going further risks muscle loss, nutrient deficiencies, and metabolic slowdown.
The 1919 Harris-Benedict equation was developed on a small sample of mostly healthy college students. The 1990 Mifflin-St Jeor equation used a broader population sample and has been validated to be accurate within 10% for 82% of people in modern studies, vs. 70% for Harris-Benedict.
Track a typical week. "Sedentary" means a desk job and no planned exercise. "Lightly active" is 1–3 leisurely gym sessions. "Moderately active" is 3–5 proper workouts. "Very active" is intense daily training. Research shows most people overestimate by one category — when in doubt, go lower.
In terms of weight, a calorie is a calorie. But for health, satiety, and body composition, food quality matters enormously. 500 calories of chicken + vegetables keeps you full much longer than 500 calories of cookies, which spike blood sugar and lead to faster hunger return.
Total Daily Energy Expenditure (TDEE) = BMR × Activity Multiplier. Sedentary (desk job, little exercise) uses 1.2x. Light activity (1–3 days/week exercise) uses 1.375x. Moderate (3–5 days) uses 1.55x. Very active (6–7 days) uses 1.725x. These multipliers approximate the calories burned through daily movement and exercise beyond your basal metabolic rate.
For weight loss, a deficit of 500 calories/day below TDEE results in approximately 1 pound lost per week — a safe, sustainable rate. For muscle gain, a surplus of 250–500 calories/day supports lean mass growth. Never go below 1,200 calories (women) or 1,500 calories (men) daily without medical supervision, as this risks nutritional deficiency.