Weight management is fundamentally about energy balance: calories consumed versus calories expended. While the biology is complex, the core math provides a reliable starting framework that you can refine with real-world data.
Step 1: Calculate Your BMR
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161 BMR is the energy your body burns at complete rest — just to keep organs functioning. Calculate yours with the BMR Calculator.
Example: A 30-year-old man, 180 cm, 85 kg: BMR = 10(85) + 6.25(180) - 5(30) + 5 = 850 + 1125 - 150 + 5 = 1,830 calories/day.
Step 2: Calculate Your TDEE
| Activity Level | Multiplier | Example (BMR 1,830) |
|---|---|---|
| Sedentary (desk job) | 1.2 | 2,196 cal |
| Lightly Active (1-3 days/week) | 1.375 | 2,516 cal |
| Moderately Active (3-5 days/week) | 1.55 | 2,837 cal |
| Very Active (6-7 days/week) | 1.725 | 3,157 cal |
Step 3: Set Your Deficit
A pound of body fat contains approximately 3,500 calories. A 500 calorie daily deficit produces roughly 1 lb/week loss. A 1,000 calorie deficit produces roughly 2 lbs/week — the maximum recommended rate. Never eat below your BMR for extended periods. Plan your deficit with the Calorie Deficit Calculator.
Calculate your exact deficit with adaptive thermogenesis modeling
Try the Calorie Deficit Calculator →Key Takeaways
- BMR is your baseline — never eat below it for extended periods.
- TDEE = BMR × activity multiplier is your total daily calorie expenditure.
- 500 cal/day deficit ≈ 1 lb/week, but metabolic adaptation slows this over time.
- Track for 2-3 weeks and adjust based on actual weight trends, not just calculations.