Basal Metabolic Rate (BMR) is the number of calories your body requires to maintain basic life-sustaining functions while at rest, such as breathing, circulation, and cell production. It is the largest component of total daily energy expenditure. Common formulas used to calculate BMR include:
- Mifflin-St Jeor Equation: Considered the most accurate for most people.
- Revised Harris-Benedict Equation: An earlier formula, still in use.
- Katch-McArdle Formula: Takes lean body mass into account, useful for leaner individuals.
The Mifflin-St Jeor formula, for men and women respectively, is:
- Men: BMR=10×weight (kg)+6.25×height (cm)−5×age (years)+5BMR=10\times \text{weight (kg)}+6.25\times \text{height (cm)}-5\times \text{age (years)}+5BMR=10×weight (kg)+6.25×height (cm)−5×age (years)+5
- Women: BMR=10×weight (kg)+6.25×height (cm)−5×age (years)−161BMR=10\times \text{weight (kg)}+6.25\times \text{height (cm)}-5\times \text{age (years)}-161BMR=10×weight (kg)+6.25×height (cm)−5×age (years)−161
After calculating BMR, total daily calorie needs can be estimated by multiplying BMR by an activity factor, ranging from 1.2 (little or no exercise) up to 1.9 (very active with physical job) depending on activity level. BMR calculators are widely available online to input height, weight, age, and gender to compute estimates. These calculators help in understanding how many calories are needed to maintain your body at rest before factoring in activity levels.
If a specific BMR calculation is needed, providing height, weight, age, and sex would allow computing the exact value using the formula.
