TDEE Calculator (UK)
✅ Scientific Mifflin-St Jeor Formula | ✅ 5 Activity Level Multipliers | ✅ Dietitian-Reviewed 2026
Use our free TDEE calculator to estimate your Total Daily Energy Expenditure — the total number of calories your body burns in a 24-hour period. Find your exact maintenance calories instantly.
What Is TDEE (Total Daily Energy Expenditure)?
Total Daily Energy Expenditure (TDEE) represents the cumulative amount of energy (in calories) your body expends every day. Unlike your BMR, which only covers basic survival functions while at rest, TDEE accounts for all movement, workouts, and food digestion.
Your TDEE is composed of four distinct components:
- Basal Metabolic Rate (BMR) ~ 60–70%: The energy required for cell preservation, breathing, blood circulation, and organ function.
- Non-Exercise Activity Thermogenesis (NEAT) ~ 15–30%: Energy expended during daily activities like standing, working, typing, cleaning, and walking around.
- Thermic Effect of Food (TEF) ~ 10%: The energy used to digest, absorb, and process nutrients. Protein has the highest TEF, burning 20-30% of its calories during digestion.
- Exercise Activity Thermogenesis (EAT) ~ 5–10%: The calories burned during structured physical workouts like running or lifting weights.
How to Use Your TDEE to Reach Fitness Goals
Once you calculate your TDEE (maintenance calories), you can easily adjust your target calorie intake to meet your specific goal:
1. Fat Loss (Calorie Deficit)
To lose weight, you must create a deficit. Subtract 15% to 25% (typically 300 to 500 calories) from your TDEE. This creates a sustainable rate of fat loss (0.5 to 1.0 pound per week) without causing extreme hunger or slowing down your metabolic rate. Use our Calorie Deficit Calculator to refine your targets.
2. Muscle Gain (Calorie Surplus)
To build lean muscle efficiently, you must consume a surplus of calories to support muscle protein synthesis. Add 5% to 10% (typically 200 to 300 calories) to your TDEE, and ensure your protein intake is high. Use our Protein Calculator to protect and build muscle.
3. Body Recomposition
If you want to burn fat and build muscle simultaneously, eat exactly at your TDEE (maintenance). Keep protein high and perform regular weight training. This is most effective for beginners and returning lifters.
Activity Multiplier Guidelines
Your activity level is the most common source of estimation error in TDEE calculations. Use this guide to select your multiplier accurately:
| Activity Level | Multiplier | Exertion Description |
|---|---|---|
| Sedentary | 1.20 | Desk job, couch sitting, minimal standing, no intentional exercise. |
| Lightly Active | 1.375 | Standing jobs, light walking, or light workouts 1–3 times a week. |
| Moderately Active | 1.55 | Daily active movement or moderate workout sessions 3–5 times a week. |
| Very Active | 1.725 | Physical jobs (construction, farming) + intense training 6–7 times a week. |
| Athlete | 1.90 | Professional athletes, heavy manual labor + daily double training sessions. |
TDEE vs. BMR: What's the Difference?
Many people confuse BMR and TDEE. Here is the distinction:
- BMR (Basal Metabolic Rate) is the absolute minimum energy required to keep you alive. If you were in a coma and did not move all day, you would burn your BMR.
- TDEE (Total Daily Energy Expenditure) is BMR plus all the physical movement of your day. It represents your actual caloric maintenance level. Your TDEE is always higher than your BMR.
Use our BMR Calculator to find your base metabolic rate.
Related Calculators
- Calorie Calculator — Find your daily calorie and deficit requirements
- BMR Calculator — Your Basal Metabolic Rate
- Macro Calculator — Optimize your fat, protein, and carb splits
- Body Fat Calculator — Estimate body composition with US Navy method
- Weight Loss Calculator — Deficit plans and timeline to target weight
Frequently Asked Questions
How is my TDEE calculated?
TDEE is calculated in two steps. First, BMR is calculated using the Mifflin-St Jeor equation. Second, BMR is multiplied by an activity factor (1.2 to 1.9) representing your daily movement. BMR × Activity Multiplier = TDEE.
Should I eat below my TDEE to lose weight?
Yes. To lose weight, you must create a calorie deficit below your TDEE. Eating 300 to 500 calories below your TDEE daily triggers healthy fat loss of 0.5 to 1.0 pound per week while maintaining muscle mass.
Why is my TDEE calculator result different from my fitness tracker?
Calculators use population averages, while fitness trackers estimate energy burn from heart rate and motion. Fitness trackers often overestimate workout burn by 20-30%. Use this calculator as a baseline, and adjust based on actual weight trends.
How often should I recalculate my TDEE?
Recalculate your TDEE every 10–15 pounds of weight loss. As you lose mass, your body requires less energy to move, which naturally lowers your BMR and TDEE. Adjusting targets prevents plateaus.
Medically Reviewed By
Dr. Sarah Jenkins, RD — Clinical Dietitian & Metabolic Health Specialist
Dr. Jenkins has over 15 years of experience in clinical nutrition and metabolic health, specializing in evidence-based energy expenditure modeling.
Last reviewed: July 2026 | Sources: BMR Calculation Accuracy (PubMed) · NEAT and Energy Balance (NIH)