BMR & TDEE Calculator
Calculate your Basal Metabolic Rate and Total Daily Energy Expenditure using age, weight, height, and activity level. Essential for setting accurate calorie targets for weight loss, maintenance, or gain.
About this calculator
BMR (Basal Metabolic Rate) is the number of calories your body needs at complete rest to sustain vital functions such as breathing, circulation, and cell repair. This calculator uses the Mifflin-St Jeor equation, considered the most accurate for most adults. For men: BMR = 88.362 + (13.397 × weight) + (4.799 × height) − (5.677 × age). For women: BMR = 447.593 + (9.247 × weight) + (3.098 × height) − (4.330 × age). TDEE is then found by multiplying BMR by an activity factor — commonly 1.2 (sedentary) up to 1.9 (very active). The result is your estimated daily calorie requirement for weight maintenance. Adjusting calorie intake above or below TDEE drives weight gain or loss respectively.
How to use
Example: Male, 30 years old, 75 kg, 178 cm tall, moderately active (activity factor 1.55). Step 1 — BMR: 88.362 + (13.397 × 75) + (4.799 × 178) − (5.677 × 30) = 88.362 + 1,004.775 + 854.222 − 170.31 = 1,777 kcal. Step 2 — TDEE: 1,777 × 1.55 = 2,754 kcal/day. This means eating roughly 2,754 calories per day maintains current weight. To lose 0.5 kg/week, subtract ~550 calories for a daily target of about 2,200 kcal.
Frequently asked questions
What is the difference between BMR and TDEE and which one should I use for dieting?
BMR is the calories your body burns doing absolutely nothing — lying still in a temperature-neutral environment. TDEE builds on BMR by adding the energy cost of all your daily movement, exercise, and the thermic effect of food. For dieting, always use TDEE as your baseline, then apply a deficit from there. Eating at your BMR level without accounting for activity would create an excessively large, unsustainable deficit for most people.
How accurate is the Mifflin-St Jeor equation for calculating BMR?
The Mifflin-St Jeor equation is widely regarded as the most accurate predictive formula for resting metabolic rate in typical adults, with studies showing it estimates BMR within about 10% for most individuals. It outperforms older equations like Harris-Benedict in controlled comparisons. However, it does not account for body composition — a very muscular individual will have a higher true BMR than the formula predicts, while someone with low muscle mass may have a lower one. For the most accurate measurement, indirect calorimetry in a clinical setting is the gold standard.
What activity multiplier should I use when calculating my TDEE?
Activity multipliers typically range from 1.2 for sedentary lifestyles (desk job, little exercise) to 1.9 for extremely active individuals (hard physical labour plus daily intense training). The most common values are 1.375 for light activity (1–3 days of exercise per week), 1.55 for moderate activity (3–5 days), and 1.725 for very active individuals (6–7 days of hard training). Most people overestimate their activity level, so when in doubt it is safer to start with a lower multiplier and adjust based on real-world weight changes over 2–4 weeks.