Calorie Need Calculator
Estimate your basal metabolic rate and total daily calorie needs based on age, weight, height, sex, and physical activity level, using the Mifflin-St Jeor equation commonly used by nutrition professionals. 100% local calculation.
How it works
Basal metabolic rate (BMR) is the energy your body expends at complete rest to maintain vital functions. This tool uses the Mifflin-St Jeor equation, now considered one of the most accurate for estimating BMR, then multiplies the result by an activity factor to get your total daily energy expenditure.
Why apply a 500 kcal deficit or surplus?
A calorie deficit of about 500 kcal per day compared to your maintenance level corresponds, in theory, to losing about 0.5 kg per week (1 kg of fat represents about 7,700 kcal). Conversely, a surplus of 500 kcal per day promotes gradual weight gain, useful for example when the goal is lean muscle gain combined with appropriate training.
Is this estimate valid for everyone?
It gives a good approximation for most adults, but it remains a statistical average: actual metabolism varies depending on body composition, genetics, health status (thyroid, pregnancy, breastfeeding...) and other individual factors. For a specific health goal, consulting a professional is still recommended.
Your personal health data never leaves your browser: the calculation is completely local.