TDEE Calculator Formula
Understand the math behind the tdee calculator. Each variable explained with a worked example.
Formulas Used
TDEE (Calories/day)
tdee = bmr * activity_factorBMR (Calories/day)
bmr_display = bmrWeekly Calories
tdee_weekly = bmr * activity_factor * 7Variables
| Variable | Description | Default |
|---|---|---|
weight_lbs | Weight(lbs) | 170 |
height_inches_total | Height (total inches)(inches) | 70 |
age | Age(years) | 30 |
activity_factor | Activity Level | 1.55 |
weight_kg | Derived value= weight_lbs * 0.453592 | calculated |
height_cm | Derived value= height_inches_total * 2.54 | calculated |
bmr | Derived value= 10 * weight_kg + 6.25 * height_cm - 5 * age + 5 | calculated |
How It Works
TDEE - Total Daily Energy Expenditure
TDEE = BMR x Activity Factor
TDEE represents the total calories you burn per day including exercise and daily activities.
Activity Factors
Worked Example
A 30-year-old male, 170 lbs, 70 inches, moderately active.
- 01BMR = 10(77.1) + 6.25(177.8) - 5(30) + 5 = 1,737
- 02TDEE = 1,737 x 1.55 = 2,692 cal/day
- 03Weekly = 2,692 x 7 = 18,844 cal/week
When to Use This Formula
- Setting precise macronutrient and calorie targets for a structured diet plan where you need to know total daily burn, not just resting metabolic rate.
- Comparing energy expenditure across different training programs — switching from weightlifting 3 days a week to daily running significantly changes your multiplier and total burn.
- Calculating the calorie deficit or surplus needed for a specific rate of weight change, since TDEE is the baseline from which you add or subtract.
- Adjusting nutrition during injury recovery when activity drops sharply but your body still needs adequate calories for healing.
- Planning meal prep quantities for the week by multiplying your daily calorie target (derived from TDEE) by seven to get weekly totals for shopping.
Common Mistakes to Avoid
- Using the wrong BMR formula for your population — the Mifflin-St Jeor equation is more accurate for most people than the older Harris-Benedict, which overestimates by 5-15% in overweight individuals.
- Selecting "very active" because you feel tired — the activity multiplier is based on actual physical movement, not perceived fatigue. A stressful desk job is still sedentary even if it is exhausting.
- Treating TDEE as a fixed number — it fluctuates daily based on steps, fidgeting (NEAT), sleep quality, and temperature. The calculated value is an average starting point, not a precise daily figure.
- Double-counting exercise calories — if you select "active" as your activity level, the multiplier already includes regular exercise. Adding back calories burned from a workout on top of that leads to overeating.
Frequently Asked Questions
What is TDEE?
TDEE is the total number of calories your body burns in a day, combining BMR (resting metabolism) and calories burned through activity.
How do I use TDEE for weight loss?
Eat below your TDEE to lose weight. A deficit of 500 cal/day leads to about 1 lb loss per week.
Learn More
Guide
How to Calculate Daily Calories: A Complete Guide
Learn how to calculate your daily calorie needs using BMR, TDEE, and activity multipliers. Understand calorie deficits, surpluses, and how to set targets for your goals.
Ready to run the numbers?
Open TDEE Calculator