TDEE Calculator

TDEE represents the total number of calories your body burns in a single day, including all physiological processes and physical activity. It is composed of four components: Basal Metabolic Rate (BMR, 60-75% of total), Thermic Effect of Food (TEF, ~10%), Exercise Activity Thermogenesis (EAT), and Non-Exercise Activity Thermogenesis (NEAT). TDEE is the single most important number for managing your weight, whether your goal is fat loss, muscle gain, or maintenance.

TDEE is calculated in two steps. First, your Basal Metabolic Rate (BMR) is estimated using a validated equation such as Mifflin-St Jeor (1990) or Katch-McArdle (1996). The Mifflin-St Jeor equation uses sex, age, weight, and height: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161. Second, BMR is multiplied by a Physical Activity Level (PAL) factor ranging from 1.2 (sedentary) to 1.9 (extra active) to produce your TDEE.

A good TDEE is one that supports your specific health goals. For weight maintenance, consume calories equal to your TDEE. For sustainable fat loss, aim for a 300-500 calorie deficit below your TDEE, which typically produces 0.3-0.5 kg (0.7-1 lb) of weight loss per week. For lean muscle gain, add 200-350 calories above your TDEE. The average adult TDEE ranges from 1,600 to 3,000 calories per day, varying significantly based on body size, composition, and activity level.

TDEE calculators using the Mifflin-St Jeor equation are accurate within approximately 10% for about 82% of the population, according to a comprehensive review by Frankenfield et al. (2005) published in the Journal of the American Dietetic Association. However, individual variation exists due to genetics, hormonal factors, muscle mass, and non-exercise activity thermogenesis (NEAT). The calculator provides a scientifically grounded starting point; adjust your intake based on actual weight changes tracked over 2-3 weeks for the most reliable results.

For most people, the Mifflin-St Jeor equation (1990) is the best choice. It is recommended by the Academy of Nutrition and Dietetics as the most accurate predictive equation for resting energy expenditure in the general population. If you know your body fat percentage with reasonable accuracy (from DEXA scan, hydrostatic weighing, or quality calipers), the Katch-McArdle formula may be more precise, particularly if you are very muscular. The Harris-Benedict equation is still widely used but tends to overestimate BMR by about 5% for modern populations.

Yes. Your TDEE represents the total number of calories your body burns each day, including basal metabolic functions, digestion, and all physical activity. Eating at your TDEE should maintain your current weight. If you consistently eat at your calculated TDEE and notice weight changes of more than 0.5 kg (1 lb) over two weeks, recalculate your TDEE as your body composition may have shifted, or adjust your intake by 100-200 calories in the appropriate direction.

To lose fat, consume fewer calories than your TDEE. A moderate deficit of 300-500 kcal/day below TDEE produces sustainable fat loss of approximately 0.3-0.5 kg (0.7-1 lb) per week. This is based on the principle that one pound of body fat stores approximately 3,500 kcal. During a cut, increase protein intake to 1.6-2.2 g/kg body weight to preserve lean muscle mass. Avoid aggressive deficits larger than 25% of TDEE, which can trigger metabolic adaptation and muscle loss. Recalculate your TDEE every 4-6 weeks as your weight decreases.

To gain muscle, consume calories above your TDEE. For a lean bulk that minimizes fat gain, add 200-350 calories per day to your TDEE and pair this with a structured resistance training program. For faster weight gain, add 500 calories daily, though a larger proportion may be stored as fat. Ensure adequate protein intake of 1.6-2.2 g/kg body weight to support muscle protein synthesis. Monitor your weight weekly; if you are gaining more than 0.5% of body weight per week during a lean bulk, reduce your surplus slightly.

Recalculate your TDEE every 4-6 weeks during an active cutting or bulking phase, as changes in body weight directly affect your BMR. You should also recalculate whenever your activity level changes significantly (new exercise program, change in occupation activity), after a body weight change of 5 kg (10 lbs) or more, or at minimum every 3-6 months for general maintenance purposes. As you age, BMR naturally declines, making periodic recalculation important for accuracy.

Yes, TDEE decreases with age. Basal metabolic rate declines approximately 1-2% per decade after age 20, primarily due to loss of lean muscle mass (sarcopenia) and hormonal changes. The Mifflin-St Jeor equation accounts for this through its age variable. However, this decline is not inevitable at the rate most people experience it; regular resistance training and adequate protein intake can significantly preserve muscle mass and keep metabolic rate higher than age-predicted values.

Several factors cause discrepancies. MyFitnessPal uses the Mifflin-St Jeor equation but applies slightly different activity multipliers and rounds values differently. More significantly, MyFitnessPal adds exercise calories on top of your baseline TDEE, which can lead to substantial overestimation since the activity multiplier already accounts for exercise. Their activity level descriptions also differ from standard Physical Activity Level (PAL) values used in research. Our calculator uses standardized multipliers from peer-reviewed literature for consistency.

The most common mistakes include: overestimating your activity level (choose the lower option when unsure), eating back exercise calories on top of your TDEE (the activity multiplier already includes exercise), not adjusting your TDEE as you lose or gain weight, relying on fitness tracker calorie estimates which can be off by 20-40%, and expecting the calculator to be exact rather than using it as a starting point. Track your actual weight changes over 2-3 weeks and adjust your intake by 100-200 calories based on real results.