User Rating 0.0
Total Usage 1 times
Loss (-20%)MaintainGain (+20%)
Maintenance
Is this tool helpful?

Your feedback helps us improve.

About

Energy balance dictates body composition changes, yet accurate estimation remains a hurdle for professionals and individuals. Total Daily Energy Expenditure is not a static number; it fluctuates based on non-exercise activity thermogenesis and metabolic adaptation. Reliance on generic multipliers often results in caloric targets that are either too aggressive, causing muscle loss, or too conservative, stalling progress. This tool integrates the Mifflin-St Jeor equation, widely considered the gold standard for clinical settings, with granular activity factors.

Understanding the distinction between Basal Metabolic Rate and TDEE is critical for dietary planning. While BMR represents the energy required for homeostasis, TDEE accounts for the thermic effect of food and physical exertion. Inaccurate input regarding activity levels is the primary cause of failure in nutritional protocols. This calculator isolates these variables, offering a baseline for caloric intake adjustments relative to specific weight modulation goals.

TDEE BMR macros metabolism calorie-deficit

Formulas

The core estimation utilizes the Mifflin-St Jeor equation for Basal Metabolic Rate (BMR), adjusted by an activity factor (γ).

Men: BMR = {

10W + 6.25H 5A + 5

Women: BMR = {

10W + 6.25H 5A 161

Total Expenditure: TDEE = BMR × γ

Where W is weight in kg, H is height in cm, A is age in years, and γ is the activity multiplier derived from MET (Metabolic Equivalent of Task) averages.

Reference Data

Activity ClassificationMET RangeMultiplier γTypical Examples
Sedentary1.0 - 1.51.2Office work, reading, driving, no dedicated exercise
Lightly Active1.6 - 2.91.375Walking 30 min/day, household chores, standing work
Moderately Active3.0 - 5.91.55Brisk walking, light cycling, resistance training 3-5x/week
Very Active6.0 - 8.91.725Construction work, heavy lifting, high-intensity sports 6-7x/week
Extremely Active 9.01.9Professional athletes, double-day training sessions, ultra-endurance
Thermic Effect (Protein)N/A1.2 - 1.3Digestion of lean meats, whey, egg whites (High TEF)
Thermic Effect (Fats)N/A1.0 - 1.05Digestion of oils, nuts, avocados (Low TEF)
Metabolic AdaptationN/AVarAdaptive thermogenesis response to prolonged deficit (-10% to -15%)

Frequently Asked Questions

Weight fluctuation is rarely solely due to fat tissue changes. Factors such as glycogen retention (water weight), sodium intake, cortisol levels from stress, and intestinal content volume cause daily variance. A calculated deficit assumes a linear biological response, but the body often retains water to maintain cellular pressure during lipolysis (fat breakdown).
Protein has a higher Thermic Effect of Food (TEF) compared to fats and carbohydrates. Approximately 20-30% of the calories from protein are expended during digestion, compared to 0-3% for fats. While standard TDEE formulas do not explicitly separate TEF, high-protein diets effectively increase the net energy expenditure, allowing for slightly higher intake while maintaining a deficit.
Recalculation is necessary after any significant change in body weight (greater than 5-10 lbs) or a shift in activity lifestyle. As body mass decreases, BMR drops because there is less tissue to support. Failing to adjust caloric intake to a new, lower body weight is a common cause of the "plateau" phenomenon.
Mifflin-St Jeor is generally accurate but can underestimate caloric needs for individuals with exceptional lean body mass. Muscle tissue is more metabolically active than adipose tissue at rest. For bodybuilders or strength athletes, adding a 5-10% buffer to the calculated maintenance calories is standard practice to prevent performance decrements.