BMR and TDEE explained
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to keep you alive — breathing, circulation, cell repair. Your Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor, and it represents roughly how many calories you burn in a normal day. TDEE is the number that matters for managing weight.
How this calculator works
It uses the Mifflin-St Jeor equation, the formula most dietitians consider the most accurate for the general population. It takes your sex, age, height and weight to find BMR, then applies your activity level to get TDEE. To lose weight, eat below your TDEE; to gain, eat above it. A 500-calorie daily deficit or surplus is a common, sustainable target for roughly half a kilo (about a pound) per week.
Tips for using the numbers
- Treat the result as a starting estimate, then adjust based on real progress over 2-3 weeks.
- Don't drop too low — very aggressive deficits are hard to sustain and can cost muscle.
- Protein and strength training help preserve muscle while losing fat.
- Weigh yourself consistently (same time, same conditions) to see the trend.
Frequently asked questions
Which formula is used?
Mifflin-St Jeor, widely regarded as the most accurate BMR formula for most people.
Why a 500-calorie change?
A 500/day deficit or surplus is a common target for about 0.5 kg (1 lb) per week. Adjust to your needs.
Is this medical advice?
No. It's an estimate for general guidance. Consult a professional for personalised advice.