Basal metabolic rate calculator and definition - base metabolic rate

Thank you for visiting our page on the Basal Metabolic Rate, which is also referred to as the Base Metabolic Rate or Basal Metabolism. Here we are going to provide you with a breakdown of what the Basal metabolic rate is starting with a comprehensive definition, we are also going to provide you with a Basal Metabolic Rate formula or Basal Metabolic Rate calculator as it is often referred to, for both males and females.

Basal Metabolic Rate definition

So what is Basal Metabolic Rate? The Basal Metabolic Rate, often referred to as your BMR or Base Metabolic Rate, is what your body requires at rest(sleeping) in order to maintain normal functions and bodily processes such as breathing and heartbeat, these basic functions are known as the mechanical and thermometric functions. The body's mechanical and thermometric functions require a base level of energy as a must. Up to 75% of your energy is used by the body when it rests to carry out these functions with a further 10% used to digest and metabolise the food that you have eaten.

We all use energy all of the time irrespective of what we are doing. We use energy when we eat, we use energy when we exercise and we even use energy when we are fast asleep. We have provided you with a Basal Metabolic Rate calculator below so that you can calculate your Basal Metabolic Rate in order to ascertain the number of calories you would burn if you were to remain in bed all day sleeping.

There are several ways to increase your basal metabolism and thus increase Basal Metabolic rate and they are highlighted on the other pages on this site, the most effective methods are exercise, making sure that your diet is loaded with metabolism boosting foods and also by drinking plenty of water, for further details see our page on natural metabolism boosters.

Your Basal Metabolic Rate is something that unfortunately decreases with age, which means as you get older the harder it becomes to eat anything yet still remain slim, something that is a blessing for younger people with a fast metabolism. Many people think that the logical thing to do is starve their body of food in order to lose weight, this has an adverse effect as it will actually decrease your Basal Metabolic Rate. The way to beat a slow metabolism and a decreasing Basal Metabolic Rate is to exercise regularly, eat healthily and drink lots of water.

Basal Metabolic Rate calculator

The following Basal Metabolic Rate formula is used by the World Health Organization and can be used as a simple guideline for you to calculate your Basal Metabolic Rate from the comfort of your own home. The purpose of the Basal Metabolic Rate calculator is to determine how many calories an individual needs to burn at a minimum, as this works out the calories required for a body that is resting for the day and not physically exerting itself. The figure you will get from the Basal Metabolic Rate calculator is your daily caloric needs.

Basal Metabolic Rate formula for women - [ 655+(9.6 x weight kg) + (1.7 x height cm) - (4.7 x age) ]

Basal Metabolic Rate formula for men - [ 66+(13.7 x weight kg) + (5 x height cm) - (6.8 x age) ]

The above equation does not take into account your body composition, which is a measurement of the percentages of both muscle and fat that your individual body is comprised of. Therefor it is less accurate if you have a non-typical amount of muscle because muscle burns calories, whereby fat does not.
A person who has an above average amount of muscle will have a higher Basal Metabolic Rate or Resting Metabolic Rate than calculated; a person with a below average amount of muscle will have a lower Basal Metabolic Rate or Resting Metabolic Rate than calculated.

If your aim is to reduce your weight by burning off excess body fat, try to eat 500 less calories each day than your daily caloric needs, and also maintain or increase your exercise activity.

As your Resting Metabolic Rate only represents resting energy expenditure, an adjustment needs to be made to reflect your level of activity. You can do this by multiplying your RMR or BMR by an activity factor (this factor was put forward by McArdle et al 1996).

Activity Factor

• 1.2 - Sedentary - Little to no exercise each day
• 1.375 - Lightly Active - Light exercise or sports 1-3 days each week
• 1.55 - Moderately Active - Light exercise or sports 3-5 days a week
• 1.725 - Very Active - Hard Exercise or sports 6-7 days a week
• 1.9 Extremely Active - Hard daily exercise or sports plus a physical occupation

By using these activity factors you are gaining a very loose estimate of the total daily energy expenditure or in simple terms the amount of calories you should be burning off in a normal day, and there are many different opinions on what these activity factors should actually be.

How accurate is the Basal Metabolic Rate formula?

There are several variations as to how you can calculate Basal Metabolic Rate, the most commonly used Basal Metabolic Rate formulas are the Harris-Benedict equation(very close to as shown above) and the Mifflin equation(more commonly used for calculating the Resting Metabolic Rate). These equations though only provide you with an estimate and are not set in stone. Metabolic rates vary significantly between similar people and it is even possible for the Basal Metabolic rate to change from day to day in the same person!

The following assumptions are made at the time that the Basal Metabolic Rate is calculated:

• * The person is awake - When you are asleep your Basal Metabolic Rate drops by around 10%
• Thermal neutrality - There is minimal variations to your ambient temperature, for example you are not as hot as you would be if you were sat in a sauna
• Little to no emotional disturbance - If you are in a non-neutral emotional state this can effect your Basal Metabolic Rate, for instance if you are angry or worked up your Basal Metabolic Rate can increase up to 40%
• You must be resting - At the time you cannot be performing activity that is working your muscles, you have to be relaxed
  * Post-absorptive state - It must be 12 hours or more following your last meal for the Basal Metabolic formula to be accurate

In order for the Basal Metabolic rate calculation to be as accurate as possible the above must be adhered to as closely as possible.

We hope that this page has been of use to you in finding out the answer to the common question 'What is Basal Metabolic Rate?', please check out our other pages including our page on the Resting Metabolic Rate calculator, our main page on a range of metabolism boosting foods that you can include in your metabolism diet and also our page on the many different ways to increase metabolism that they are.