What You Need to Know About Your
Basal Metabolic Rate

Basal Metabolic Rate (BMR) is an excellent place to start if you're trying to understand your body's essential energy requirements better. BMR measures the energy your body needs to carry out the daily functions that keep it balanced. The list of functions includes things that are automated but do require energy (calories or kilojoules).

So think digestion, brain function, body temperature regulation, breathing etc. This energy accounts for about 60% of the total energy used in the day and omits energy burned via activity. BMR is simply the amount of energy used to maintain homeostasis.

Use our basal metabolic rate calculator to find out how many calories or kilojoules your body needs at rest to fuel its normal metabolic activity.

Basal Metabolic Rate Calculator


  • BMR:
  • PROTEIN (g)
  • FAT (g)

Why is BMR important?

Our bodies naturally burn calories throughout the day to sustain everyday life functions - including breathing, digestion, keeping our heart beating, and other tasks our body needs to sustain itself.

Imagine your body is a car, and all the food and drinks you consume fuel your car to move.
The best way to determine how much physical fuel (food and drinks) your body needs is to know your BMR.

We are all different and spend different amounts of food on providing energy for our basic functions. Once you know your BMR, you can calculate how much you need to eat, depending on your weight loss goal.

Basal metabolic rate is calculated at rest when we do not spend energy on activities except basic functions.

Calculating your BMR could help determine how many calories to cut out each day if you are trying to create an energy deficit to lose weight. Sometimes, this may mean consuming only enough calories to support your BMR.

Alternatively, if you want to gain weight, use a BMR calculator to determine how many extra calories you must consume daily.

What are the important factors of BMR?

Your metabolic rate is determined by several factors, some of which you have direct control over and others you do not.

Those factors include:

  • • Age

    Because of muscular tissue loss and changes in hormonal and neurological processes, your metabolic rate commonly slows down as you age.

  • • Gender

    Men have more muscle mass and a lower body fat percentage. Men, therefore, have a higher basal metabolic rate than women.

  • • Body composition & weight

    Those that weigh more have a higher BMR because they must maintain greater organs and fluid volume.

  • • Physical activity

    Exercise builds muscle mass and increases your metabolic rate, which burns calories quicker even when you're not moving.

  • • Genetics & ethnicity

    Some families have faster BMR than others, with some genetic disorders affecting metabolism. Different diets might also bring this on among different ethnicities.

  • • Diet

    Food changes your metabolism. What and how you eat has a big influence on your BMR.

    Crash dieting, starving or fasting – eating too few kilojoules encourages the body to slow the metabolism to conserve energy. BMR can drop by up to 15 per cent, and if lean muscle tissue is also lost, this further reduces BMR.

This is a massive deal - why?

This is why the YO YO or roundabout effect of restricted food intake, weight loss, then weight regain, and more when you return to regular eating habits. It can be why you feel defeated, and long-term weight loss is somewhat unattainable.

These factors show that you can change some things to alter your BMR, and others can't. The good news is that you can do plenty to alter the balance.

How do I calculate my BMR?

You can use a metabolic rate calculator to determine how many calories you burn daily to have a basic starting point for reaching your goals.

Bariatric Surgery, Bariatric Multivitamins, Weight Loss Surgery, Bariatric Vitamins in Australia
  • If you are on the Weight Loss Surgery journey, your starting weight will also mean your BMR is high - so as your body reduces in size, so will your baseline energy requirements each day. You must be aware that you simply need fewer calories each day. However, if you find yourself more active and muscular, some of this will be mitigated by an increased metabolic rate.
  • Adding muscle to your body is one major key to long term success. Muscle is termed "metabolically active", meaning it uses energy even when you are sitting at your desk. It’s like having more muscle on your frame to adding a V8 motor to your car - just idling at the lights will need more fuel.
  • Get Started! Suppose you want to lose weight, build muscle, or maintain weight. Use our BMR calculator to learn your basal metabolic rate and the next steps toward your fitness goals!

Frequently Asked Questions

  • How do I calculate my BMR?

    The basal metabolic rate formula below can be used to calculate your basal metabolic rate:

    • BMR for men is equal to 88.362 + 13.397 * weight (kg) + 4.799 x height in cm - (5.677 x age in years)
    • BMR for women is calculated as follows: 447.593 + 9.247 * weight (kg) + 3.098 x height in cm - (4.330 x age in years)
  • How is BMR affected by age?

    BMR declines as we age. Compared to adults, children have a higher BMR. It decreases by roughly 2% per decade after 20 years of age.

    An average man has a BMR of around 7,100 kJ (1697 calories) per day, while an average woman has a BMR of approximately 5,900 kJ (1410 calories) per day. Energy expenditure is continuous, but the rate varies throughout the day. The rate of energy expenditure is usually lowest in the early morning.