How to use this calculator
- 1
Enter your profile
Choose gender and age. Metabolic rate declines slightly with age and differs by sex due to body composition.
- 2
Add weight and height
Switch between metric and imperial. Use your morning weight for the most consistent result.
- 3
Pick an honest activity level
Most people overestimate activity. If you have a desk job and train 3x/week, choose 'Light' or 'Moderate'.
- 4
Use the targets
Start with the target for your goal, track your weight for 2–3 weeks, then adjust by 100–200 kcal if needed.
Real-world example
Alex, a 30-year-old man, 80 kg and 180 cm, trains 4 times per week (Moderate). His BMR is 1,780 kcal and TDEE about 2,759 kcal. To lose ~0.5 kg/week he aims for ~2,259 kcal; to build muscle, ~3,059 kcal with 1.6–2.2 g/kg protein.
Features, accuracy & limitations
Formula: Mifflin-St Jeor equation (BMR = 10×kg + 6.25×cm − 5×age + 5 for men, −161 for women), multiplied by an activity factor from 1.2 to 1.9.
Key features
- Mifflin-St Jeor — the most validated equation for healthy adults
- Metric and imperial units
- Real-time results as you adjust inputs
- Targets for loss, maintenance and gain
Limitations
- Typically accurate within ±10% for most adults
- Does not account for body fat percentage or muscle mass
- Not designed for pregnancy, under-18s or medical conditions
- Activity multipliers are population averages
Medical disclaimer: This calculator provides estimates for informational and educational purposes only. It is not a medical diagnosis and does not replace advice from a doctor, registered dietitian, or other qualified health professional. Consult a professional before making changes to your diet, exercise, or health routine — especially if you are pregnant, under 18, or have a medical condition.