The BMR calculator or basal metabolic rate calculator can be a handy tool for many people involved in fitness or just have particular weight goals. This article will inform you about what you need to know about BMR, how it works, and why you should use a BMR calculator [below] if you aren’t already.

What is BMR?

So, what is BMR, and what does it mean exactly? The acronym BMR stands for basal metabolic rate, and it refers to the energy that is expended while at rest. The words “at rest” do not necessarily mean sleeping specifically, as the BMR is a daily occurrence. In layman’s terms, the basal metabolic rate definition can be explained as the bare minimum calories required to sustain your life. [1]

Calories are simply a unit of energy and it can be quantified. You have probably seen calories listed millions of times on the nutrition label on almost everything that you have consumed in your lifetime.

Most people are concerned about how many calories are burnt while doing certain activities, especially exercise. However, the body also burns calories to maintain vital functions while you are doing absolutely nothing. You are still burning calories even if you are laying around in bed and sleeping.

The vital functions of your body that are consuming energy can include:

• breathing
• circulation
• digestion

These processes obviously don’t stop when you’re at rest, and calories are required to keep them working around the clock. But how many calories are used to keep your body working as intended? That’s where the BMR calculator comes in.

What is My BMR?

Not everyone burns the same amount of calories, and in regards to the BMR calculator, a few factors are considered. The parameters that are taken into account for when trying to calculate BMR. The details that you will need to know are:

• age
• height
• weight
• biological sex

Depending on whether you are male or female, a basal metabolic rate formula will be different. The numbers that are used to determine the outcome will be slightly adjusted. These will be discussed in the next section.


How To Calculate BMR?

In the previous section, we briefly explained what goes into calculating BMR. Finally, for those who are wondering, “what is my BMR?”, these are the formulas (based on the Harris-Benedict equation) that are used to provide you with an answer to that question. [2]:

Harris-Benedict BMR Calculator for Men:

h = 66.4730 + (13.7516 x weight in kilograms) + (5.0033 x height in centimeters) – (6.7550 x age)

Harris- Benedict BMR Calculator for Women:

h = 655.0955 + (9.5634 x weight in kilograms) + (1.8496 x height in centimeters) – (4.6756 x age in years)

These formulas are based on the metric system, so if you are living in one of the few countries that use the imperial system, such as the USA, you may need to do a quick conversion of your height and weight from inches and pounds, to centimeters and kilograms, respectively.

The variable, “h”, in these basal metabolic rate formulas essentially means the same thing as BMR. This variable stands for heat. The creators of these formulas, J. Arthur Harris and Francis Benedict, used this because when energy is expended, it produces heat.

Another formula that is often helpful in showing you how to calculate BMR is the Mifflin-St. Jeor equation. While the Harris-Benedict equation has been popular and reliable even with clinics, some cases have shown in both obese and non-obese people that the Mifflin-St. Jeor equation to be more accurate [3]. Here is the Mifflin-St. Jeor equations for both men and women: [4]

Mifflin-St. Jeor BMR Calculator for Men:

RMR = (10 x weight in kilograms) + (6.25 x height in centimeters) – (5 x age) + 5

Mifflin-St. Jeor BMR Calculator for Women:

RMR = (10 x weight in kilograms) + (6.25 x height in centimeters) – (5 x age) – 161

RMR, in this equation, stands for resting metabolic rate and therefore is interchangeable with the basal metabolic rate. Heat, RMR, and BMR are all synonymous with each other. Therefore, a resting metabolic rate calculator essentially means that will calculate BMR.

BMR Calculator vs TDEE calculator: What’s the Difference?

You may have heard of a TDEE calculator at least once in your lifetime. TDEE stands for Total Daily Energy Expenditure. Like BMR, TDEE can also be calculated and also involves burnt calories. However, unlike a resting metabolic rate calculator, there is a different between these two.

Simply put, BMR or RMR, only deals with energy that is being burned during rest – the number is based on if you are doing nothing, especially sleeping. TDEE calculates the energy that is being used throughout the entire day while you go about your daily routines. Keep in mind, your TDEE also includes BMR.

Both are closely related, but when trying to use a metabolic rate calculator for an entire 24 hour period through TDEE, you need to rate your physical activity level. This can depend on:

• Your type of profession
• Exercise habits

Depending on these, usually, this calculator will have you rate it anywhere from being completely sedentary to being extremely active. There are in-between options. For example, there are teachers and restaurant servers who may be on their feet constantly but don’t exercise. This allows the calculator to be more precise.

Why Is BMR Important?

Based on the last section, it may seem like at first glance that a TDEE calculator is better than a BMR calculator. While TDEE is more comprehensive, both have specific purposes.

BMR is useful in understanding how many calories are required to allow your organs to do their daily jobs and keep you alive. TDEE calculators are commonly used to figure out how many calories are burned throughout a day, based on physical activity. If you’ve been having trouble choosing a metabolic rate calculator, this is how to you can make the distinction.

However, it is important to note that BMR has a huge part in contributing to your total energy expenditure. In fact, it is the largest. [1] Without an understanding of BMR, the TDEE calculator would probably have never existed. It can be thought of as foundational for comprehending metabolism and thermogenesis.

Since, BMR has a significant role in overall calories burnt in a day, taking a look at your basal metabolic rate, can still be effective in combating weight issues. Once you have the number from the BMR calculator provided to you, consume fewer calories than this number consistently on a daily basis, in order to lose weight. This is known as a caloric deficit and it is a common term used in fitness circles. This is how you use a BMR calculator to lose weight.

Are BMR Calculators Accurate?

The simple answer to this question is “yes”. BMR calculators are accurate and have been tried and tested by physicians, fitness professionals, and the general public for many years. However, what is the most accurate basal metabolic rate calculator?

We’ve briefly delved on this in the section that introduced you to the most common equations used to calculate BMR. While that particular study had shown the Mifflin-St. Jeor equation to be more accurate, others have shown that the Harris-Benedict equation to be just as precise.

The study that claimed that the Mifflin-St. Jeor equation to have higher accuracy, found that this equation predicted BMR within 10 percent in both obese and non-obese people [4]. On the other hand, a separate study had shown that the Harris-Benedict equation predicted within 10 percent as well. [5]

The accuracy of these calculators can be situational and also depend on some factors. The study that supports the Mifflin-St. Jeor equation involved ordinary individuals, whereas the one that backed the Harris-Benedict equation involved police officers with irregular shift work. Certain situations and professions can alter basal metabolic rate in people.

How Can You Raise BMR?

By now, you have a lot of information on what is basal metabolic rate, but you’re also probably wondering how you can influence it. Basal metabolic rate varies from person to person, and it can largely depend on a number of factors. These can include: [6]

• genetics
• gender
• age
• anthropometric characteristics
• body composition

Four out of these five things can’t be controlled. However, the one that you can change is your body composition. Your body is composed of fat, bone, water, and muscle. When people measure body composition typically body fat percentage is what is looked at, as well as overall lean body mass.

Usually, when people are leaner, they often have higher metabolisms, sometimes even naturally because of some of the aforementioned factors. Luckily, you can take matters into your own hands and improve your metabolic rate. Here are some options that you can try out:

• build some muscle
• increase the intensity of your cardio routine
• drink more water
• include more spicy foods in your diet
• consume more protein
• have caffeine (in moderation!)

To expand on these points, muscle tends to burn more calories overall, not just at rest, so building muscle should be beneficial to those looking to increase their energy expenditure. Aerobic exercise, such as cardio, can be a great tool to burn calories and lose weight and increase your BMR.

However, the intensity needs to be stepped up in the gym, if you are only exercising with low to moderate-intensity. There are many ways you can have an intense cardio session and here are a few that you can choose from:

• go running
• use a jump rope
• perform jumping jacks or burpees
• go bike riding
• use a stair climber machine

Water is definitely something that shouldn’t be shrugged off either. It contains zero calories, which allows calories from foods to be burnt first, but more importantly, staying hydrated by consuming at least 500 ml of water, can increase metabolic rate by up to 30 percent [7].

Consuming spicy food can have a small and temporary boost in metabolism, so it’s worth a try even if you don’t have a palate for spiciness. Out of the three macronutrients (fats, carbs, and protein), protein has the highest thermogenic effect [8]. It will be beneficial to include more protein in your diet not only for this but also for adding muscle.

Lastly, caffeine, which you can get from coffee and tea, has been shown to have a huge effect on metabolic rate [9]. Caffeine can also give you that extra drive you may need for an intense workout.

Summary & Conclusion

No matter who you are, you need calories to stay alive. Hopefully, this article has given you a great deal of information on what is basal metabolic rate, how you can apply it to yourself, and answer questions such as “what is my BMR?” or “why is BMR important?”.

By using a basal metabolic rate calculator, you can figure out how many calories are burnt at rest and are allowing your organs to function properly. These calculators are often based on the Harris-Benedict equation as well as the Mifflin-St. Jeor formula because they have been reliable for many people.

While a TDEE may be slightly more ideal because it’s more comprehensive, using a BMR calculator to lose weight is still extremely helpful. This is because most of the calories you burn are during rest. By understanding BMR, you can effectively try to tackle weight issues. Without BMR, TDEE would have never come to be as well.

A BMR calculator is also easy to use and they are also quite accurate. All you need to do is input your height, weight, age, and your biological sex. It’s that simple! You don’t necessarily need to use the formulas that are listed here. These just show what online BMR calculators are derived from and show you how to calculate BMR if you were to do it manually.

While the basal metabolic rate is dictated by a few different things, namely your genetics, gender, age, and the structure of your body. You can still make an impact on it through other methods. You can change your composition as well as take advantage of meaningful exercise and consume foods and drinks that promote a faster metabolism.

Don’t underestimate the value of understanding your BMR. By using a BMR calculator, you are in the right direction of gaining knowledge of how your body works. If you have a weight problem, this is a great step to take. Put yourself in a caloric deficit, by eating fewer calories than the number the BMR calculator gives you, and you’ll be setting yourself up for weight loss if you do this daily. The key is consistency.

Obesity (or being just overweight) doesn’t need to be permanent and it can be combated by taking a strategic approach. Avoid crash diets, learn how your body works, and manage your calories appropriately, and you should see steady progress if you calculate BMR!


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2. Harris, J. A., & Benedict, F. G. (1918). A Biometric Study of Human Basal Metabolism.
Proceedings of the National Academy of Sciences, 4(12), 370-373.

3. Frankenfield, D., Roth-Yousey, L., & Compher, C. (2005). Comparison of Predictive Equations
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and Mifflin-ST Jeor equations with indirect calorimetry in evaluating resting energy expenditure. Indian Journal of Medical Sciences, 62(7), 283. doi:10.4103/0019-

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6. Lazzer, S., Bedogni, G., Lafortuna, C. L., Marazzi, N., Busti, C., Galli, R., . . . Sartorio, A. (2010). Relationship Between Basal Metabolic Rate, Gender, Age, and Body Composition in 8,780 White Obese Subjects. Obesity, 18(1), 71-78. doi:10.1038/oby.2009.162

7. Boschmann, M., Steiniger, J., Hille, U., Tank, J., Adams, F., Sharma, A. M., . . . Jordan, J. (2003). Water-Induced Thermogenesis. The Journal of Clinical Endocrinology & Metabolism, 88(12), 6015-6019. doi:10.1210/jc.2003-030780

8. Pesta, D. H., & Samuel, V. T. (2014). A high-protein diet for reducing body fat: Mechanisms and possible caveats. Nutrition & Metabolism, 11(1), 53. doi:10.1186/1743-7075- 11-53

9. Acheson, K. J., Zahorska-Markiewicz, B., Pittet, P., Anantharaman, K., & Jéquier, E. (1980). Caffeine and coffee: Their influence on metabolic rate and substrate utilization in normal weight and obese individuals. The American Journal of Clinical Nutrition, 33(5), 989-997. doi:10.1093/ajcn/33.5.989