Basal Metabolic Rate Calculator

What is BMR? 

Basal metabolic rate, or BMR, is the amount of energy your body needs to perform basic functions such as respiration, cardiac function, homeostasis, and so on.

BMR is determined by gender, age, and body weight. 60-70% of daily energy expenditure comes from basal metabolism.

When you’re trying to lose weight, many people focus on the number on the scale. But that’s not the best way to measure your progress—your basal metabolic rate (BMR) is a much better indicator.

What is BMR Calculator?

The Basal Metabolic Rate calculator is a simple tool used to estimate the basal metabolic rate of your body and measure the kilocalories required to sustain life processes at rest—essentially, what your body needs to keep you healthy. 

Because BMR measures the rate at which one’s body burns calories when a person is resting, it can only be accurately calculated after fasting for 12 hours and getting a whole night’s sleep—with no physical activity or emotional excitement. 

Why is BMR Calculator important?

Because it gives you an idea of how many calories you burn every day at rest—understanding your BMR allows you to set realistic fitness goals, including losing weight or gaining muscle mass. If you know how many calories your body needs each day, you can use the information to ensure the foods and drinks you consume provide enough energy without causing a caloric surplus or deficiency. This is how you can utilise the BMR calculator to lose weight or track how well your diet and exercise routine are working for you.

BMR Calculation Formula- The Harris-Benedict equation revised by Roza and Shixgal

To calculate your BMR, you need to know your weight, height, age, and gender and add those details to the basal metabolic rate formula (like the one below) to determine how many calories you need to burn daily to maintain normal healthy physiology.

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)

This calculation is not always accurate because it does not consider other activities or exercises and variables such as muscle mass, diet, weather, genetics, pregnancy, and supplements. However, it can provide a good estimate. 

Factors influencing BMR

Many factors contribute to your BMR, such as:

Resting Metabolic Rate

The energy you expend when your body is at rest is known as resting metabolic rate (RMR) or resting energy expenditure, accounting for most calories you burn daily.

RMR is typically defined as the number of calories a person burns at rest every day—without doing any physical activities or exercise.

Resting metabolic rate (RMR) differs from basal metabolic rate (BMR)- BMR is usually measured in the morning, after an overnight fast, and after no exercise for 24 hours.

Essentially, basal metabolic rate is just the energy your body uses at rest to keep vital organs going—like your heart and lungs whereas resting metabolic rate includes the extra energy expended on non-exercise daily movements—like getting out of bed, chewing or watching tv —resting metabolic rate (RMR) is generally slightly higher than basal metabolic rate.

So if you want to know how many calories you burn in a day, then you can use our online BMR calculator, but if you want to know how many calories you burn in an hour of doing something active like walking around or playing sports, then use RMR since BMR will be much lower.


The BMR calculator is an easy way to determine your calorie needs- it can give you a baseline for how many calories you need to eat every day to maintain your weight. It's not an exact measurement, but it gives you a good idea of where to start while determining your calorie consumption.

If you want to know your exact BMR calories or confirm that the figures are correct for your body type, contact our nutritionist (nutrition daily link). They will be able to help and guide you.

Checkout our BMI Calculator