Calorie Calculator
Calculate your daily calorie needs based on your age, gender, height, weight and activity level.
Disclaimer
This calculator provides estimates for general information purposes only. Results are based on standard formulas and may not reflect your individual circumstances. Always consult a qualified professional for advice specific to your situation.
Frequently Asked Questions
How accurate are calorie calculators?
How many calories should I eat to lose weight?
What is Calorie?
A calorie calculator estimates your daily energy needs (calories) based on your age, gender, height, weight, and activity level. Knowing your Total Daily Energy Expenditure (TDEE) is the foundation for any weight management plan.
How this calculator works
The calculator uses the Mifflin-St Jeor equation, which is considered the most accurate formula for estimating Basal Metabolic Rate (BMR). BMR is then multiplied by an activity factor (1.2 for sedentary up to 1.9 for extremely active) to estimate your TDEE. The results show calorie targets for five goals: weight loss (500 cal deficit), mild loss (250 deficit), maintenance, mild gain (250 surplus), and weight gain (500 surplus). A 500-calorie daily deficit typically results in approximately 0.5kg of weight loss per week.
Mifflin-St Jeor Formula
Considered the most accurate BMR formula in modern nutrition science. MEN: BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) + 5. WOMEN: BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) - 161. The 1990 Mifflin-St Jeor equation replaced the older Harris-Benedict (1919) and is preferred by most dietitians. Accurate within ~10% for most adults; less accurate for very athletic or very obese individuals.
Activity Multipliers
Sedentary (1.2): desk job, no exercise. Lightly active (1.375): light exercise 1-3 days/week. Moderately active (1.55): moderate exercise 3-5 days. Very active (1.725): intense exercise 6-7 days. Extremely active (1.9): heavy physical work + intense daily training. Most office workers vastly overestimate their activity level. If unsure, use 1.375 — over-estimating leads to over-eating.
Calorie Deficit for Weight Loss
Standard advice: 500 cal/day deficit = ~0.5kg/week loss (since 1kg fat ≈ 7,700 cal). Aggressive deficit (1,000/day) works short-term but increases hunger, muscle loss, and rebound risk. Most sustainable: 300-500 cal deficit, 0.3-0.5kg/week loss, with protein intake 1.6-2.2g/kg body weight to preserve muscle. Floor: women not below 1,200 cal/day, men not below 1,500.
Why Most Diets Fail
Metabolic adaptation: BMR can drop 10-15% on sustained low-calorie diet. Hunger hormones (ghrelin) increase. Most weight regain within 2 years. Long-term success factors: gradual loss, high protein, resistance training (preserves muscle), realistic goals, behavioural change vs short-term diet. The calculator estimates baseline; real-world maintenance often requires fewer calories than predicted due to adaptation.
Official Sources
All calculations are performed in your browser — your data never leaves your device. Results are for general guidance only and should not be considered professional financial advice.
Built and maintained by Konstantin Iakovlev. Data sourced from the ATO and official Australian government sources.