What Is TDEE?
Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a 24-hour period. It covers everything from keeping your heart beating and your lungs breathing to walking to the coffee machine and completing a tough workout. Understanding your TDEE is the single most important number for any nutrition plan — it is the baseline against which every calorie goal is set.
Your TDEE is made up of four components: Basal Metabolic Rate (BMR), the Thermic Effect of Food (TEF), Non-Exercise Activity Thermogenesis (NEAT), and Exercise Activity Thermogenesis (EAT). Of these, BMR typically accounts for 60±75% of total daily calorie burn, making it the largest single contributor. The remaining 25±40% comes from movement and digestion.
Unlike a simple BMR reading — which tells you how many calories your body needs at complete rest — TDEE reflects real life. That is why two people with identical BMRs can have very different calorie needs depending on how active they are each day.
How Your TDEE Is Calculated
This calculator uses the Mifflin-St Jeor equation, the most validated formula for estimating BMR in modern nutrition science. Developed in 1990, it consistently outperforms the older Harris-Benedict equation — particularly in people with overweight or obesity — with a typical accuracy of ±10%.
The equations 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
This BMR result — which you can also calculate in isolation using our BMR Calculator — is then multiplied by an activity factor ranging from 1.2 (sedentary) to 1.9 (extra active) to produce your TDEE. For example, a 25-year-old male weighing 70 kg at 175 cm has a BMR of 1,674 kcal. With moderate activity (—1.55), his TDEE is 2,594 kcal per day.
Using Your TDEE to Reach Your Goals
Once you know your TDEE, setting an effective calorie target is straightforward. A consistent deficit or surplus of 250–500 kcal per day drives gradual, sustainable changes in body composition without the hormonal disruption caused by extreme restriction.
- Lean bulk (+250 kcal): Steady muscle gain with minimal fat accumulation. Best for experienced lifters.
- Maintain: Eat at TDEE to hold your current weight while body recomposition occurs slowly.
- Mild loss (-250 kcal): Approximately 0.25 kg per week — the most sustainable rate of fat loss.
- Weight loss (-500 kcal): The classic deficit. Targets approximately 0.5 kg (1 lb) per week.
- Extreme loss (-750 kcal): Aggressive cut — recommended only short-term and ideally supervised.
Calorie targets alone do not guarantee results — macronutrient distribution matters too. Use our Protein Calculator to find your daily protein target, which protects lean muscle during a deficit. If you are unsure where to start, check your BMI Calculator result to contextualise your current body composition and set a realistic long-term goal.
Deficits larger than 750 kcal/day carry real risks including muscle loss, hormonal disruption, and metabolic adaptation. They should only be followed under the guidance of a qualified dietitian or physician.
Choosing the Right Activity Multiplier
The activity multiplier is the most common source of error in TDEE calculations. Most people overestimate their activity level, which sets their calorie target too high and stalls progress. Use the guidelines below:
- Sedentary (1.2): Office or desk job, fewer than 5,000 steps per day, no structured exercise.
- Lightly active (1.375): Desk job plus exercise 1–3 days per week, moderate daily steps (5,000–7,500).
- Moderately active (1.55): Exercise 3–5 days per week with moderate intensity — the most common choice for regular gym-goers.
- Very active (1.725): Hard exercise 6–7 days per week, or a physical job combined with regular training.
- Extra active (1.9): Twice-daily training, manual labour job, or elite athlete in-season.
When in doubt, choose the lower multiplier and adjust based on real-world results. Track your weight weekly for 2–4 weeks: if it stays stable while eating at your calculated TDEE, the estimate is accurate. If weight changes unexpectedly, adjust your intake by 100–150 kcal and reassess.
Scientific References: Mifflin MD, et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 51(2):241–247. — Frankenfield D, et al. (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults. J Am Diet Assoc. 105(5):775–789.