TDEE Formula
Total Daily Energy Expenditure is BMR multiplied by an activity factor. The factor is the imprecise part — even within a tier, two people can spend 400+ calories apart in non-exercise activity thermogenesis.
Formula
Copy the exact expression or work through it step by step below.
TDEE = BMR × activity_factor Variables
TDEE
Total Daily Energy Expenditure
Calories burned per 24 h including exercise, fidgeting (NEAT), and the thermic effect of food.
BMR
Basal Metabolic Rate
From Mifflin-St Jeor or an equivalent equation. Roughly 60–75% of TDEE in sedentary adults.
activity_factor
Activity multiplier
1.2 sedentary (desk job, no exercise); 1.375 light (1–3 workouts/week); 1.55 moderate (3–5/week); 1.725 very active (6–7/week or physical job); 1.9 athlete (twice-daily sessions).
Step By Step
- 1
Calculate BMR using Mifflin-St Jeor.
30-year-old male, 78 kg, 178 cm → BMR 1,747.5.
- 2
Pick the activity factor that matches the average week, not the peak week.
Lifts 4×/week, walks daily → moderate (1.55).
- 3
Multiply BMR by the factor.
1,747.5 × 1.55 = 2,708.6 cal/day.
- 4
Treat the result as a starting point. Track weight for 2–3 weeks; if it doesn't move at maintenance, adjust the factor up or down by 0.1.
If weight drifts up 0.5 kg/week at 'maintenance', actual factor is closer to 1.45 — drop 250 calories.
Worked Example
30-year-old male, 78 kg, 178 cm, lifts 4×/week
BMR
1,747.5
Activity factor
1.55 (moderate)
TDEE = 1,747.5 × 1.55 = 2,708.6 calories/day
Maintenance ~2,710 cal/day. Subtract 500 for a 1 lb/week deficit, add 250 for a lean-gain surplus.
Common Variations
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Sources & References
- Energy expenditure: methods and assumptions — European Journal of Clinical Nutrition
- Wearable device accuracy for energy expenditure — Journal of Personalized Medicine