Basal Metabolic Rate Calculator + Online Solver With Free Steps

The Basal Metabolic Rate Calculator is a free online tool that determines the total amount of calories your body needs to maintain its resting metabolic rate, also referred to as basal metabolic rate or metabolism.

Your BMR will rise as a result of anything that raises your metabolic rate. This includes physical activity, worry, fear, and ailments.

Your BMR varies depending on your height, weight, age, and body mass. Your gender also has an impact because it is generally accepted that men need more calories than women.

What Is a Basal Metabolic Rate Calculator?

The Basal Metabolic Rate Calculator is an online tool that enables you to determine how many calories your body would require if you were to spend the entire day at rest.

Your BMR score is provided by the Basal Metabolic Rate Calculator based on your age, height, weight, and gender. The amount of energy a human body consumes while in full rest is known as the basal metabolic rate.

It’s the quantity of energy required by your body to maintain its essential processes, such as breathing, blood circulation, regulating body temperature, and the operation of your brain and nerves, to mention a few.

The brain, the central nervous system, and the liver are the organs that consume the most energy when at rest. The management of fluid quantities and ion levels throughout the day uses more energy than the actual mechanical action of muscles contracting, which is intriguing (e.g., breathing).

To maintain homeostasis, we naturally adjust the concentrations and quantities of numerous substances in various parts of our body (a state of steady internal conditions).

This occasionally involves moving chemicals against a concentration (or molarity) gradient and past barrier (like cell membranes, for example). This means that particles must be moved from low-concentration space to high-concentration space, a process that consumes energy.

This translates to a lot of energy when applied to the entire body. It also explains why, in terms of Basal Metabolic Rate, our central nervous system uses so much energy. Many distinctions move about when a brain impulse is conducted. They must then be transported back to their starting point.

How To Use a Basal Metabolic Rate Calculator

You can use the Basal Metabolic Rate Calculator by following the given detailed stepwise guidelines. The calculator will provide the accurate required results in seconds. You can therefore follow the instructions to easily get the number of calories.

Step 1

Fill in the provided input boxes with Gender, Age, Weight, and Height.

Step 2

Press the “SUBMIT” button to determine the number of calories and also the whole step-by-step solution for the BMR will be displayed.

How Does Basal Metabolic Rate Calculator Work?

The Basal Metabolic Rate Calculator works by using an estimation technique that establishes the minimum number of calories you must consume each day to maintain life, assisting you in determining the total number of calories you should give your body each day.

To the number of calories determined by our BMR calculator, remember to add your energy expenditure (in calories) from other activities like walking, chatting, etc. The Basal Metabolic Rate calculator works by following the steps given below:

Step 1

First, weigh yourself and enter the result in our calculator’s Weight section.

Step 2

The second step is to measure your height and enter it in the Height field.

Step 3

Enter your age now in the Age area. Note that the age value must be expressed in years.

Step 4

Choosing your gender is the final step. You may read how it slightly modifies the Basal Metabolic Rate formula in the paragraph that follows.

The BMR Formula

To determine BMR, various formulas are employed. The Mifflin-St Jeor equation was used in this calculator since it is currently thought to provide the most accurate result.

This BMR formula is as follows:

BMR $(\frac{kcal}{day})$ = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + s $(\frac{kcal}{day})$

where s is +5 for males and -161 for females.

Additionally, we have calculators that compute your Basal Metabolic Rate using several formulas.

Harris Benedict Formula

The Harris Benedict Formula, which determines the total number of calories needed to maintain your present weight, uses your BMR calculation as input.

This is as follows:

  • Little/no exercise: BMR * 1.2 = Total Calorie Need
  • Light exercise: BMR * 1.375 = Total Calorie Need
  • Moderate exercise (3-5 days/wk): BMR * 1.55 = Total Calorie Need
  • Very active (6-7 days/wk): BMR * 1.725 = Total Calorie Need
  • Extra active (very active & physical job): BMR * 1.9 = Total Calorie Need

Solved Examples

Following are some solved examples to better understand the working and operation of the Basal Metabolic Rate Calculator.

Example 1

BMR for man calculation


We must first translate the values from imperial to metric units. This is necessary since the BMR calculation was created exclusively for use with the metric system.

150 pounds weighs the same as 68.04 kilos, or around 162.56 cm, at five feet and four inches tall.

Fortunately, both systems use the same method to determine the age. Please be aware that you can enter in a certain unit (for example, feet) and then click on the unit to change it (e.g., into meters).

The BMR for the man equation can now be filled up with all the information:

10 x 68.04 + 6.25 x 162.56 – 5 x 60 + 5 

The equation must be solved as the last step.

10 x 68.04 + 6.25 x 162.56 – 5 x 60 + 5 = 680.4 + 1016 – 300 + 5 = 1401.4 $(\frac{kcal}{day})$

And that’s it!

Example 2

BMR for women calculation


We’ll attempt to determine BMR for a woman this time. We will employ the Mifflin and St. Jeor BMR equation for women, which is a slightly different formula.

BMR $(\frac{kcal}{day})$ = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) -161 $(\frac{kcal}{day})$

The last component of these two formulations is the sole distinction, as you’ve probably already seen.

For every guy, we add five kcal per day, and for every woman, we deduct one sixty-one kcal per day.

Let’s now concentrate on a model female who is 25 years old and stands at 5 feet, 8 inches tall. She has 132 pounds on her. The calculations can start now.

The values must first be converted from imperial units to the metric unit. You can utilize the technique stated in the previous paragraph.

172.72 centimeters are equal to 5 feet and 8 inches, and 59.87 kilograms are 132 pounds. Again, age does not change.

Fill out the BMR for woman equation using the obtained values:

10 x 59.87 + 6.25 x 172.72 – 5 x 25 – 161 

Solve the original equation.

10 x 59.87 + 6.25 x 172.72 – 5 x 25 – 161 = 598.7 + 1079.5 – 125 – 161 = 1392.2 $(\frac{kcal}{day})$

As always, we recommend using our BMR calculator to confirm the outcome. There may be a slight variation in the outcomes because we made a few estimates to make the computations by hand easier.

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