Weight

Height

Age in years

Male

Female

(kg, cm)

(lbs, inches)

Calculate BMR

After calculating your BMR, you can use it to estimate your Total Daily Energy Expenditure Click Here

Basal Metabolic Rate (BMR)

Basal Metabolic Rate (BMR) is the body's energy at rest to maintain essential physiological functions such as breathing, circulation, and cell production. It represents the calories the body needs to perform these crucial functions while at complete rest, without additional physical activity. The Harris-Benedict equations are often used to estimate BMR. These equations provide separate formulas for men and women, considering differences in body composition and metabolic rates.

The formulas for BMR using the Harris-Benedict equation for adults are as follows:

1. For Men:

   BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) − (5.677 × age in years)

2. For Women:

   BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) − (4.330 × age in years)

Let's break down the components of these equations:

1. Weight (in kg): Represents the body weight in kilograms. The heavier the person, the higher the BMR because more energy is required to maintain a larger body.
2. Height (in cm): Represents the height in centimeters. Taller individuals generally have a higher BMR because more energy is needed to support a larger body surface area.
3. Age (in years): Represents the age of the individual. BMR tends to decrease with age, primarily due to reduced muscle mass. Muscles have a higher metabolic rate, so a decline in muscle mass results in a lower BMR.

Now, let's understand the significance of each constant in the equations:

• For Men:
  • 88.362 is a baseline constant.
  • 13.397 represents the contribution of weight to BMR.
  • 4.799 represents the contribution of height to BMR.
  • 5.677 represents the contribution of age to BMR.
• For Women:
  • 447.593 is a baseline constant.
  • 9.247 represents the contribution of weight to BMR.
  • 3.098 represents the contribution of height to BMR.
  • 4.330 represents the contribution of age to BMR.

By plugging in weight, height, and age values into these formulas, you can estimate the BMR, which is the number of calories your body would burn at rest. To calculate Total Daily Energy Expenditure (TDEE), you would multiply the BMR by an activity factor that reflects your level of physical activity throughout the day.