TDEE Calculator
Calculate your Total Daily Energy Expenditure (TDEE) and Basal Metabolic Rate (BMR) with the clinically validated Mifflin-St Jeor equation, custom activity multipliers, and daily macronutrient targets.
Body Metrics
Step-by-Step Mifflin-St Jeor BMR & TDEE Proof
How to Calculate Total Daily Energy Expenditure (TDEE)
To find your TDEE: 1. Calculate Basal Metabolic Rate (BMR): Men = (10 × kg) + (6.25 × cm) − (5 × age) + 5; Women = (10 × kg) + (6.25 × cm) − (5 × age) − 161. 2. Multiply BMR by your Physical Activity Level factor (1.2 to 1.9). 3. Subtract 500 kcal/day for fat loss or add 300 kcal/day for muscle gain.
Total Daily Energy Expenditure & Energy Balance
The First Law of Thermodynamics dictates body mass regulation through the biological energy balance equation ($\Delta \text{Energy} = \text{Calories In} - \text{Calories Out}$):
Organs, brain, respiration at rest
Walking, posture, typing, chores
Digesting & processing meals
Cardio, weightlifting, sports
Physical Activity Level (PAL) Multipliers
| Activity Tier | PAL Multiplier | Description & Routine |
|---|---|---|
| Sedentary | 1.200 | Desk job, little to no intentional exercise |
| Lightly Active | 1.375 | Light workouts or walking 1 to 3 days per week |
| Moderately Active | 1.550 | Moderate physical exercise 3 to 5 days per week |
| Very Active | 1.725 | Intense hard training 6 to 7 days per week |
| Extremely Active | 1.900 | Professional athletic training or heavy manual labor |
Caloric Deficit & Surplus Periodization Guidelines
Fat Loss Cut (−500 kcal)
Burns ~3,500 kcal weekly deficit (equivalent to ~1 lb of fat tissue loss per week) while keeping energy levels high.
Weight Maintenance (0 kcal)
Exact caloric parity to maintain body weight and optimize recovery between training blocks.
Lean Muscle Bulk (+300 kcal)
Provides extra metabolic energy for muscle protein synthesis and progressive resistance overload while minimizing fat storage.
Step-by-Step Worked Numerical Solutions
Problem: Find BMR, maintenance TDEE (PAL 1.55), and fat loss target for a 78kg, 178cm, 28-year-old male.
Common Pitfalls & Mistakes
Overestimating Exercise Burn
Fitness watches often overestimate workout calorie burn by 20–40%. Choose activity multipliers conservatively.
Ignoring Liquid Calories & Cooking Oils
A single tablespoon of cooking olive oil adds 120 kcal of fat that frequently goes unlogged.
Excessive Crash Dieting (>1000 kcal deficit)
Deficits exceeding 1,000 kcal trigger hormonal downregulation, thyroid slowing, and rapid muscle catabolism.
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