Your basal metabolism
Find out the energy you burn at rest.
If you enter your body fat, the calculation switches to the Katch-McArdle method for higher accuracy. Leave it blank if you don't know it.
What Is BMR?
BMR (basal metabolic rate) is the amount of energy your body spends to sustain vital functions while completely at rest. Even while just lying down, your body breathes, pumps blood, maintains temperature and renews cells — the energy for these functions is your BMR.
BMR makes up the largest part of your total daily calorie needs; in most people about 60–70% of daily energy goes to basal metabolism. The rest is spent on movement, exercise and digestion.
This value varies from person to person. Age, gender, height, weight and body composition affect BMR. In general, more muscle raises BMR, because muscle tissue burns more energy than fat even at rest.
How Is BMR Calculated?
BMR is the energy your body spends on basic vital functions while completely at rest, and it is the starting point for daily calorie needs.
The most common method is the Mifflin-St Jeor equation; it takes age, gender, height and weight into account and is considered one of the most reliable general formulas.
If your body fat is known, the calculation switches to the Katch-McArdle method based on lean mass; it is more accurate for people whose body composition differs from average.
BMR is only the resting expenditure, not your actual daily need. To reach total daily energy (TDEE), this value is multiplied by a factor between 1.4 and 2.0 based on your activity level.