The body uses energy from food and drinks to sustain bodily functions and perform physical activities. Calories are a measure of how much energy the body receives from particular foods or drinks.

When a person consumes more calories than they burn, the body stores this excess energy as body fat. When the body needs more energy than it can get from the calories it consumes, it burns the stored body fat for energy. Regular physical activity is a good way of maintaining a healthy amount of body fat.

While other forms of physical activity can be time-consuming or expensive, walking is convenient and free for people who can do so. This article discusses how to calculate the number of calories the body burns while walking, and some of the other benefits that walking has to offer.

Calories burned while walking

The number of calories that the body burns during any activity will depend on a person's basal metabolic rate (BMR) and the intensity of the activity, measured in metabolic equivalents (METs).

The formula for this is:

Calories burned = BMR x METs ÷ 24 x duration of activity in hours

It is possible to use this formula to calculate how many calories the body burns by walking.

To do this, it is first necessary to understand about BMR and METs.

BMR

Basal metabolism refers to a series of life-supporting processes that the body constantly carries out, such as breathing. The body burns calories to support these processes. The rate at which the body does this is the BMR.

The BMR varies between people. It is difficult to calculate precisely as it depends on several factors, including genetic factors that are difficult to measure. But it is possible to estimate BMR using sex, body size, and age.

The formulae to estimate BMR for males and females are:

Males:

BMR = 66 + (6.23 x weight in pounds (lbs)) + (12.7 x height in inches) - (6.8 x age in years)

Females:

BMR = 655 + (4.35 x weight in lbs) + (4.7 x height in inches) - (4.7 x age in years)

METs

METs are a measure of how much energy the body is using for a given activity.

When a person walks, the speed at which they are walking speed will determine the number of METs.

For example, walking at a slow pace of 1.7 miles per hour (mph) equates to 2.3 METs per hour. Walking briskly at a speed of 3 mph equals 3.3 METs per hour.

Making the calculation

Pulling all this information together, it is now possible to calculate how many calories the body burns while walking.

For example, a 40-year-old male who weighs 195 lbs and is 69" (5'9") in height will have a BMR of 1,885.2. If they walk at a brisk pace for 1 hour, they will burn 259.2 calories. This is because:

BMR (1,885.2) x METs (3.3) ÷ 24 x duration of activity in hours (1) = 259.2 calories