Caloric Needs Formula (TDEE)
Calculate Total Daily Energy Expenditure using TDEE = BMR × Activity Factor.
Find how many calories you need per day based on your lifestyle.
The Formula
TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day.
It combines your base metabolic rate with your physical activity level.
This is the number you need to know for weight management.
Variables
| Symbol | Meaning |
|---|---|
| TDEE | Total Daily Energy Expenditure (calories per day) |
| BMR | Basal Metabolic Rate (calories per day) |
| Activity Factor | Multiplier based on daily activity level |
Activity Factor Values
| Lifestyle | Factor | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise, desk job |
| Lightly Active | 1.375 | Light exercise 1-3 days per week |
| Moderately Active | 1.55 | Moderate exercise 3-5 days per week |
| Very Active | 1.725 | Hard exercise 6-7 days per week |
| Extremely Active | 1.9 | Very hard exercise, physical job, or training twice per day |
Example 1 (Metric)
A man with a BMR of 1,850 calories works a desk job but exercises 3 times a week. How many calories does he need?
Activity level: Moderately Active (factor = 1.55)
TDEE = BMR × Activity Factor
TDEE = 1,850 × 1.55
TDEE ≈ 2,868 calories per day
Example 2 (Imperial Starting Point)
A woman weighs 150 lbs (68 kg), is 5'5" (165 cm), is 28 years old, and has a sedentary lifestyle. Find her TDEE.
First, calculate BMR (Harris-Benedict for women):
BMR = 447.593 + (9.247 × 68) + (3.098 × 165) - (4.330 × 28)
BMR = 447.593 + 628.80 + 511.17 - 121.24 = 1,466.3 calories
TDEE = 1,466.3 × 1.2 (sedentary)
TDEE ≈ 1,760 calories per day
Weight Management Guidelines
- Maintain weight: eat at your TDEE
- Lose weight: eat 300-500 calories below your TDEE
- Gain weight: eat 300-500 calories above your TDEE
When to Use It
Use the TDEE formula when you need to:
- Determine how many calories to eat per day
- Create a calorie deficit or surplus for weight goals
- Plan meal portions and macronutrient splits
- Understand how activity level affects energy needs
TDEE is an estimate. Individual results vary based on genetics, body composition, and other factors.
Track your weight over 2-3 weeks and adjust calories based on actual results.
This formula is for general educational purposes only. It is not medical advice. Consult a healthcare professional or registered dietitian for personalised nutrition guidance.