Calculate your BMR (basal metabolic rate)
Want to know your BMR? It’s simple with our BMR calculator – use our calculator to check your BMI with ease. This means you can find out how many kilocalories your body burns per day. Enter your details into the calculator fields to find out your BMR and ideal daily calorie intake.
What is BMR?
BMR (basal metabolic rate) refers to the energy your body needs when at rest in order to maintain your body’s vital functions such as breathing, metabolism, circulation, processing nutrients and temperature regulation, etc. This energy requirement is known as the basal metabolic rate or, alternatively, the resting metabolic rate or resting energy expenditure.
If you want to find out your ideal daily calorie or energy intake because you are on a diet, for example, it’s useful to know your own personal metabolic rate, i.e. your BMR. An adult human burns 60–75% of calories if they have an average activity level, even with just the energy required for basic bodily functioning to stay alive. The basal metabolic rate (average adult) is distributed across the different organs as follows:
Distribution of the resting energy requirement to the individual organs.
How is BMR calculated?
Over the past 100 years, numerous scientists have researched BMR calculations. Originally, these calculations were used to measure thyroid functionality in humans. Nowadays, BMR is standard for measuring an individual’s metabolism, which changes with age, weight and height, as well as due to medical conditions.
Seven different BMR formulas prevail. We use the Mifflin-St Jeor Equation for our BMR calculator. It is also used by the Academy of Nutrition and Dietetics. Developed in 1990, this formula also considers modern lifestyles. Another formula is the Harris Benedict Equation, which originated in 1918.
In 2005, different formulas for calculating BMR were compared1
and contrasted. For the calculation of BMR, the Mifflin St Jeor Equation demonstrated significantly greater accuracy in comparison to the other formulas.
Factors considered for the calculation:
- Weight = m
- Height = l
- Age = t
BMR formula for women:
BMR [kcal/day] = 10,0m
BMR formula for men:
BMR [kcal/day] = 10,0m
Can I influence my BMR?
You can increase your BMR and calorie consumption by increasing your muscle mass. Fact: Muscle cells burn more calories than fat cells and that applies even when your body is at rest. Thus reducing the amount of fat in your body mass, e.g. by increasing your muscles, increases your BMR and your body’s energy consumption.
Another point which is perhaps even more pertinent is age. By the age of 40 at the latest, metabolism changes and our bodies switch from growth to focusing on the maintenance of body mass. Metabolism slows down and with it our daily energy needs (see table below). The ratio of fat to muscle cells also transforms in favor of fat cells: The percentage of body fat increases and muscle mass reduces.
Age-related changes to BMR taking the example of a man weighing 80 kg with a height of 180 cm:
|20 years old
|30 years old
|40 years old
|50 years old
|60 years old
|70 years old
David Frankenfield, MS, RD | Lori Roth-Yousey, MPH, RD | Charlene Compher, PhD, RD Comparison of Predictive Equations for Resting Metabolic Rate in Healthy Nonobese and Obese Adults