RMR: What Is Resting Metabolic Rate?

Use a Resting Metabolic Rate Calculator or Compute Your Own

Resting metabolic rate (also called RMR) is the rate at which your body burns energy when it is at complete rest. You can calculate your resting metabolic rate to see how many calories your body needs to perform basic functions like breathing and circulation. Your RMR or resting metabolic rate is part of your total daily energy expenditure (TDEE) or the total number of calories you burn each day.

What Is Metabolism and Metabolic Rate?

We often talk about metabolism as if it is a single mechanism in your body. But it's not. Metabolism—including resting metabolism—is a series of functions that are happening all the time. The rate at which those functions occur is your metabolic rate.

Your body converts the food you eat into energy in order to fuel both basic and complex functions like breathing or moving. This process is called metabolism. The entire metabolic process is a series of chemical actions that keep your body alive and healthy.

So how does metabolism work? Every food you eat contains nutrients. Your body absorbs the nutrients and converts them into units of heat—or calories. The energy—the calories—that are provided by the food are either used right away or stored for your body to use later. Extra calories are usually stored as fat.

What Is Resting Metabolic Rate?

Resting metabolism is the energy required by your body to perform the most basic functions when your body is at rest. These essential functions include things like breathing, circulating blood or basic brain functions. Resting metabolic rate is often used interchangeably with basal metabolic rate. However, while your RMR refers to the number of calories your body burns while at rest, your basal metabolic rate (BMR) is the minimum number of calories your body burn to just exist, without any external influences.

Although BMR is slightly more accurate, the difference is only notable in clinical settings. Not only is RMR an accurate estimate of BMR, it is sufficient for determining your daily calorie needs, and easy to calculate. You can calculate your resting metabolic rate to find out your personal number.

Everyone's resting metabolism or BMR is different. Factors that affect your RMR include your weight, gender, age, and body composition. For example, someone who is very large and muscular needs more energy (more calories) to maintain his body at rest than someone who is very small.

How to Calculate Resting Metabolic Rate

Many calorie calculators, like the one at Verywell Fit, determine your RMR, then account for your daily exercise and non-exercise activity to determine the number of calories you burn each day. But you can also get your resting metabolic rate with an online calculator, by doing the math yourself, or by going to a gym or lab.

Resting Metabolic Rate Calculator

The easiest way to get your RMR is to use a quick and easy resting metabolic rate calculator. Remember that if you search for one, you can search for "resting metabolic rate calculator" or "basal metabolic rate calculator" and both will provide the same number.

You can also use these links to find a reliable RMR calculator:

In order to use one of these online resting metabolic rate calculators, you simply need to know your height, your weight, your age, and your gender.

Calculate Your RMR

If you love math, you can also calculate resting metabolic rate on your own. The Harris-Benedict Equation is often used to estimate basal or resting metabolic rate (BMR or RMR).

Harris-Benedict Equation for BMR:

  • 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)

Calculate RMR in a Lab

Some health clubs and clinics can do metabolic testing to provide you with your resting metabolic rate. The test usually takes an hour or so and is often combined with testing to determine your calorie needs and heart rate targets for exercise.

So what can you expect from the test? Popular testing protocols require that you wear a mask for a short period of time (around 15 minutes) while resting. The mask measures the exchange of gasses to determine the number of calories you burn when your body is at complete rest.

If you do exercise testing as well, you'll wear the mask while on a treadmill or a bike to determine how many calories you burn while your body is working.

Is My RMR Normal?

Once you know your RMR, you might be tempted to compare your number to the RMRs of other people around you. And you might wonder if your RMR is normal. But each person is unique so don't expect your number to match up to your workout buddy's RMR or your family member's RMR.

According to several sources, the average RMR for women is around 1400 calories per day. The average RMR for men is just over 1600 calories. But just because your number is above or below the average is not an indicator of whether or not your RMR is normal.

Women: Average BMR 1,400 calories per day

Men: Average BMR just over 1,600 calories per day

Can I Change My RMR?

If you change your body weight, your resting metabolic rate will change. An increase in weight will lead to an increase in your RMR, while weight loss will lower your RMR. Also, as you age, resting metabolic rate usually decreases. Other than that, however, you can't really change your resting metabolic rate.

But just because you can't change your RMR doesn't mean that you can't change your metabolism. In addition to your resting metabolism, there are several other factors that affect the total number of calories that you burn each day.

  • We use energy to chew and digest food. Researchers call this the thermic effect of food (TEF). It makes up a very small part of your total energy requirements. 
  • You can also burn a lot of calories with exercise. For example, you might boost your metabolism with a daily walk or a vigorous workout at the gym.
  • Non-exercise movement also requires a lot of energy. Researchers use the term "non-exercise activity thermogenesis (NEAT)" to describe all of the calories that you burn doing basic movement throughout the day like carrying groceries, walking to your desk at work, or cooking dinner. 

Change Your Metabolism to Lose Weight

To lose weight effectively, you should know your resting metabolic rate and the total number of calories you burn each day (including exercise and NEAT). There are different ways to determine those numbers, but none is an exact science. Some gyms or medical centers offer metabolic testing services that may be more accurate.

Keep in mind that the number you get when you calculate your resting metabolic rate is simply an estimate. Even if you go to the gym or to a lab, the number you get isn't exact. It is simply the best guess at the number of calories that your body will burn. This is helpful to know if you are trying to gain or lose weight. Some experimentation is always required to get your calories in (food intake) to balance out with calories out (metabolism) to reach your desired goal.

Once you have a smart estimate of how many calories you burn each day, you can change your daily food intake or change your daily activity level to create an energy deficit. Sometimes weight loss experts call it a calorie deficit.

When you don't give your body the energy it needs, it burns stored energy (stored fat) as fuel instead. The result is that you lose weight and slim down. A weekly calorie deficit of approximately 3500 calories will result in roughly one pound of weight loss.

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Article Sources

  1. Blunt K, Dye M. Basal metabolism of normal women. J Biol Chem. 1921.