Calculate Your Basal Metabolic Rate to Lose Weight

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by Anisha Shah, MD

Basal metabolic rate (BMR) is the total number of calories that your body needs to perform basic, life-sustaining functions. These basal functions include circulation, breathing, cell production, nutrient processing, protein synthesis, and ion transport. You can calculate the basal metabolic rate using a mathematical formula.



Some experts use the terms basal metabolic rate (BMR) and resting metabolic rate (RMR) interchangeably. These two terms are very similar. But there is a slight difference in the definition of BMR and the definition of RMR that is helpful to understand.

  • Basal metabolic rate is a measurement of the number of calories needed to perform your body’s most basic (basal) functions, like breathing, circulation and cell production. BMR is most accurately measured in a lab setting under very restrictive conditions.
  • Resting metabolic rate is a measurement of the number of calories that your body burns at rest. Resting metabolic rate is usually measured in the morning before you eat or exercise and after a full night of restful sleep.

As you can see, the definitions of RMR and BMR are almost identical. Your resting metabolic rate should be an accurate estimate of your basal metabolic rate. Because the terms are similar, some fitness and weight loss experts use both terms to describe the same thing. But the term “resting metabolic rate” is more common.

Calculate Your BMR

If you are looking to reach or maintain a healthy weight may find it helpful to calculate your BMR. You can either find the number using a formula designed by scientists, you can get it tested in a lab, or you can use an online calculator. No method is perfectly accurate, but a lab test will probably give you the best estimate.

But since lab tests can be costly, many dieters and exercisers use one of the other two methods to determine basal metabolic rate and/or the total number of calories they burn each day.

Equation to Calculate Your BMR

The Harris-Benedict Equation is often used to estimate basal metabolic rate.

  • Men: BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)
  • Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)

Online BMR Calculator

Put your height, weight, and age into our online calculator to find your basal metabolic rate with the addition of daily activity. The calculator provides you with an estimate of the total number of calories you burn each day.

Use BMR to Lose Weight

Once you understand BMR and you get a good estimate of your number, you can use it to help you reach or maintain a healthy weight. First you can try to increase your basal metabolic rate, then you can increase the total number of calories you burn each day to help you reach your goal.

Change Your BMR

A combination of factors determines your basal metabolic rate. Genetic factors, age, gender and body composition all play a role. There’s not much you can do to control genetics, age or gender. But you can change your body’s fat to muscle ratio to boost your metabolism.

So how do you change your body composition? Build muscle! Even when your body is at rest, lean muscle mass will burn more calories than fat. And you don’t even have to be a bodybuilder to see benefits. Several studies have shown that after just a few weeks of resistance training you may be able to see a 7%-8% increase in resting metabolic rate.1

Increase Daily Calorie Expenditure

The total number of calories you burn each day is heavily dependent on your basal metabolic rate. But you can also burn more calories each day by making changes to your diet and activity level.

Your basal metabolic rate combined with two other factors can give you an idea of the total number of calories you burn each day.

  • Basal metabolic rate accounts for about 60%-75% of total calories burned each day. Increase muscle mass to burn more calories.
  • Activity thermogenesis: (non-exercise movement and exercise) accounts for about 15%-30% of total calories burned each day. Increase daily movement to burn more calories.
  • Thermic effect of food: (calories burned from eating and digestion) accounts for about 10% of total calories burned each day. Choose healthy protein-rich foods to make a small difference.

If you can burn more calories than you consume, you will create a calorie deficit or negative energy balance.

A calorie deficit of 500-1000 calories per day should result in a 1-2 pound weight loss per week.

A Word From Verywell

Learning about your basal metabolic rate and the total number of calories you burn each day is a positive step in the process of reaching or maintaining a healthy weight. The more you know, the easier it is to make changes in your life that produce real results.

Track your numbers, keep a weight loss journal, gather support from friends and family, and connect with your healthcare team to find a plan that works over the long-term for you.