Your basal metabolic rate (BMR) is the energy (in calories) your body needs at rest each day to maintain vital functions—breathing, circulation, cell repair, and temperature regulation. Knowing your BMR gives you a baseline for setting calorie targets whether you’re looking to maintain, lose, or gain weight.

Understanding Your BMR

BMR accounts for the majority of your daily calorie burn—typically around 60–70%. Resting metabolic rate (RMR) is a closely related measure, often slightly higher because it accounts for minimal movement and the energy cost of digestion.

How BMR Is Calculated

Harris-Benedict Equation

Women:
BMR = 655.1 + (9.563 × weight in kg) + (1.850 × height in cm) – (4.676 × age in years)

Men:
BMR = 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) – (6.75 × age in years)

Mifflin-St Jeor Equation

Women:
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

Men:
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5

Other Formulas

  • Katch-McArdle: Adjusts for body fat percentage for a more precise RMR in very lean individuals.
  • Schofield (WHO): Uses body weight alone with age- and sex-specific constants.

Factors Influencing Your BMR

Age

Metabolic rate peaks in early adulthood and declines gradually—about 1–2% per decade after age 20—due to hormonal changes and loss of lean tissue.

Gender

On average, men have a higher BMR than women, largely because of greater muscle mass and different hormonal profiles.

Body Composition

Lean tissue (muscle) is metabolically active—each pound of muscle burns more calories at rest than an equivalent amount of fat. Strength training helps preserve and build muscle, supporting a higher BMR over time.

Genetics

Genetic factors account for significant individual variation in resting energy expenditure, meaning innate metabolic rates differ from person to person.

Estimating Daily Calorie Needs

To translate your BMR into a total daily calorie target, multiply by an activity factor:

  • Sedentary (little/no exercise): BMR × 1.2
  • Lightly active (light exercise 1–3 days/week): BMR × 1.375
  • Moderately active (moderate exercise 3–5 days/week): BMR × 1.55
  • Very active (hard exercise 6–7 days/week): BMR × 1.725
  • Extra active (very hard exercise or physical job): BMR × 1.9

From here:

  • To lose weight: Subtract about 500 kcal/day for roughly 1 lb (0.45 kg) of weekly fat loss.
  • To gain weight: Add about 250–500 kcal/day for gradual muscle or weight gain.

Practical Tips to Support Healthy Metabolism

  1. Build and preserve muscle. Strength training boosts lean mass, helping maintain a higher BMR.
  2. Try high-intensity interval training (HIIT). Short bursts of intense activity can elevate your post-exercise calorie burn.
  3. Eat sufficient protein. Protein has a higher thermic effect than fats or carbs and supports muscle repair and growth.
  4. Stay hydrated. Even mild dehydration can slightly lower resting metabolic rate.
  5. Don’t skip meals. Regular eating intervals keep your metabolic “furnace” stoked—especially breakfast.
  6. Get adequate sleep. Poor sleep disrupts metabolism-regulating hormones.
  7. Spice it up. Compounds like capsaicin in chili peppers and catechins in green tea may give a modest metabolic boost.

Disclaimer: This information is intended for reference purposes only and does not replace professional medical advice. Always consult a qualified healthcare provider before making significant changes to your diet, exercise, or medical regimen.