Free calculator
Calorie Calculator
Enter sex, age, weight, height and activity. The result shows BMR, maintenance calories and the target for your goal.
How daily calories are estimated
The calculator uses the Mifflin-St Jeor equation, which is the usual clinical estimate for resting energy expenditure. For men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5. For women: the same formula with −161 instead of +5. The result is multiplied by an activity factor from 1.2 (sedentary) to 1.9 (very active) to estimate maintenance calories.
The goal adjustment adds or subtracts 250 or 500 kcal per day, roughly 0.25 or 0.5 kg of body weight per week. A deficit that is too aggressive tends to reduce adherence and lean mass, so a moderate deficit is usually more sustainable.
Protein
The protein figure is a common strength-training reference of 1.6 g per kg of body weight per day. It is a starting point, not a prescription; medical conditions and kidney disease require individual advice.
Frequently asked questions
How accurate is the Mifflin-St Jeor equation?
It is within about 10% for most adults but can be further off for very muscular, very lean or older people. Use it as a starting point and adjust after two weeks.
Should I eat back exercise calories?
The activity multiplier already includes exercise. Adding calories again would double count them.
Is a 500 calorie deficit safe?
For many adults it is a moderate deficit of about 0.5 kg per week, but medical conditions, pregnancy and medication require professional advice.
How much protein do I need?
The page uses 1.6 g per kg as a strength-training reference. Needs vary with age, activity and health status.