A calorie calculator estimates the number of calories your body needs each day to maintain its current weight. It first calculates your Basal Metabolic Rate (BMR) — the calories needed at complete rest — then multiplies by an activity factor to give your Total Daily Energy Expenditure (TDEE). This calculator uses the Mifflin-St Jeor equation, which is widely regarded as the most accurate formula for most people.

1. Enter your age in years.
2. Select your biological sex.
3. Enter your height in centimetres.
4. Enter your weight in kilograms.
5. Select your activity level.
6. Click Calculate.

Female, 30 years, 165 cm, 65 kg, moderately active (×1.55).
BMR = 10×65 + 6.25×165 − 5×30 − 161 = 650 + 1,031.25 − 150 − 161 = 1,370 kcal
TDEE = 1,370 × 1.55 ≈ 2,124 kcal/day

Your TDEE is the number of calories needed to maintain your current weight. To lose weight, aim for a deficit of 300–500 kcal/day. To gain weight, aim for a surplus of 300–500 kcal/day. These are estimates — individual metabolism varies.

• Overestimating activity level — most people are sedentary or lightly active.
• Using the result as a precise target rather than a starting estimate.
• Ignoring that calorie needs change as weight, age and activity change.

What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to keep organs functioning. TDEE (Total Daily Energy Expenditure) adds the calories burned through daily activity and exercise.

How accurate is this estimate?

The Mifflin-St Jeor equation is accurate to within about 10% for most people. Individual metabolism varies due to genetics, muscle mass, hormones and other factors. Use the result as a starting point and adjust based on real-world results.

Can I use this for weight loss planning?

Yes, as a rough guide. A deficit of 500 kcal/day typically produces about 0.5 kg of weight loss per week. However, consult a healthcare professional before making significant dietary changes.