TDEE Calculator
Total Daily Energy Expenditure
What Is TDEE?
Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a single day. It is one of the most important numbers in any fitness, weight loss, or muscle-building plan because it tells you exactly how many calories you need to maintain your current weight. Eat less than your TDEE and you will lose weight; eat more and you will gain; eat exactly at your TDEE and your weight stays the same.
TDEE is made up of three components: your Basal Metabolic Rate (BMR) — the calories burned just to keep you alive at rest (breathing, circulation, cell repair); the Thermic Effect of Activity (TEA) — calories burned through intentional exercise; and the Thermic Effect of Food (TEF) — calories burned digesting food (roughly 10% of intake).
The Mifflin-St Jeor Equation
This calculator uses the Mifflin-St Jeor Equation to calculate BMR, which is then multiplied by your activity level to produce your TDEE. The Mifflin-St Jeor formula, published in 1990, has been repeatedly validated in peer-reviewed studies as the most accurate BMR prediction formula for most adults compared to the older Harris-Benedict equation (which consistently overestimates by 5%).
The formulas are:
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Activity Level Multipliers Explained
Your BMR is multiplied by an activity factor to estimate real-world calorie burn:
- Sedentary (×1.2): Desk job, minimal walking, no structured exercise
- Lightly active (×1.375): Light exercise 1–2 days per week, or walking-heavy job
- Moderately active (×1.55): Moderate exercise 3–5 days per week
- Heavy (×1.725): Hard exercise 6–7 days per week or physical labor job
- Athlete (×1.9): Two-a-day training sessions or very demanding physical profession
Most people overestimate their activity level. If in doubt, choose one level lower than you think — it is easier to add calories back than to wonder why you are not losing weight.
How to Use Your TDEE for Your Goals
- Maintain weight: Eat at your TDEE
- Lose weight (~1 lb/week): Eat 500 calories/day below TDEE. Aim for at least 0.7–1g of protein per lb of bodyweight to preserve muscle
- Lose weight (~0.5 lb/week): Eat 250 calories/day below TDEE (a more sustainable deficit)
- Gain muscle (lean bulk): Eat 200–300 calories/day above TDEE with high protein intake
Frequently Asked Questions
Does TDEE change over time? Yes — as you lose weight, your BMR decreases because you have less body mass to maintain. Recalculate your TDEE every 10–15 lbs of weight change.
Why am I not losing weight at a deficit? TDEE calculators provide estimates. If your weight is not changing after 2–3 weeks, track your actual food intake carefully — most people undercount by 20–30%. Also consider adaptive thermogenesis, where the body reduces BMR somewhat in response to sustained deficits.
Should pregnant or breastfeeding women use this? No. The Mifflin-St Jeor equation is not validated for pregnancy or lactation. Consult your OB/GYN for calorie guidance during these periods.
⚠️ Medical Disclaimer: TDEE estimates are for informational purposes only and are not a substitute for professional medical or dietary advice. Individual metabolism varies. Consult a registered dietitian or physician before making significant changes to your diet or exercise routine.