Free Calorie Calculator
Find your maintenance calories and sensible loss or gain targets — powered by the Mifflin-St Jeor equation.
Daily calories
Estimates only — not medical advice. Talk to a clinician or dietitian for personal guidance.
How to use the calorie calculator
- Enter your age, sex, height, and weight (switch between metric and imperial).
- Pick the activity level that best matches your week.
- Read your maintenance calories plus gentle loss and gain targets.
How it works: the Mifflin-St Jeor equation
This calculator uses the Mifflin-St Jeor equation, widely considered the most accurate formula for estimating basal metabolic rate (BMR) — the calories your body burns at complete rest just keeping you alive. For men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women, the same formula ends with − 161 instead of + 5. Your BMR is then multiplied by an activity factor (1.2 for sedentary up to 1.9 for very active) to get your TDEE — total daily energy expenditure — which is the number that actually matters for weight management. A daily deficit of about 500 calories typically leads to roughly half a kilo of fat loss per week, which is why the mild-loss target sits 500 below maintenance. Remember these are estimates: metabolism varies with muscle mass, hormones, and genetics, so treat the numbers as a starting point and adjust based on real results over a few weeks.
Frequently asked questions
What is BMR vs TDEE?
BMR (basal metabolic rate) is what you burn at total rest. TDEE (total daily energy expenditure) adds everything else — walking, working, exercising. TDEE is the number to eat around for weight maintenance.
How accurate is the Mifflin-St Jeor equation?
It is the most validated formula available and lands within about 10% for most people. Very muscular or very lean individuals may burn more than it predicts, since muscle is metabolically expensive.
How many calories should I eat to lose weight?
A deficit of 300–500 calories per day is the sustainable sweet spot for most people — roughly 0.25 to 0.5 kg per week. Crash diets backfire; slow and steady preserves muscle and keeps the weight off.
Does this replace medical advice?
No. This is a planning estimate, not medical guidance. If you have a medical condition, are pregnant, or have a history of disordered eating, work with a clinician or registered dietitian instead.