Before you can plan what to eat, you need to know what your body spends. The starting point is your basal metabolic rate — the calories your body burns just keeping you alive.
TL;DR — Enter your age, sex, height and weight in the BMR calculator to see the calories you burn at rest.
What BMR covers
Your basal metabolic rate is the energy your body uses at complete rest: breathing, circulating blood, maintaining temperature, repairing cells. It is the single biggest chunk of most people’s daily calorie burn — often 60–70% of the total — even before you move a muscle.
How it’s calculated
This calculator uses the Mifflin-St Jeor equation, the formula most dietitians trust today. It estimates BMR from your sex, age, height and weight. Larger bodies and more muscle raise it; age tends to lower it gradually.
Why it’s the foundation
BMR alone is not what you eat — you also burn calories moving around. But it is the base that everything else builds on. Add your activity to BMR and you get your TDEE, the calories you need to maintain weight. Adjust from there to lose or gain. So getting BMR right is the first step in any sensible calorie plan. Find yours in the BMR calculator.