Everyone knows that people need a minimum amount of calories to survive. If we don’t eat enough calories we will lose weight; if we take in too many, our weight will go up.

The big question is: how many calories should we consume on a daily basis to maintain a healthy weight. We could take a guess, but that would, of course, be inaccurate. Simple online calorie calculators, on the other hand, could definitely give us a more defined answer, but still would not be completely accurate, for the simple reason that everyone’s metabolic rate is unique.

If you want to use an online calorie calculators look for those who use more than one formula to calculate your results. They can include:

-          The Mifflin-St Jeor equation, which is based on body weight;

-          The Harris-Benedict formula, which takes Lean Mass, or fat percentage in account;

Calculate your Basal Metabolic Rate (BMR) not once, but for various levels of physical activity.

Basal Metabolic Rate (BMR)

Most online calorie calculators are able to estimate your Basal Metabolic Rate (BMR), or the amount of energy you need per day. A simple BMR only includes limited activity, such as resting in bed the entire day. If you are more active, you will have to include your level of activity to receive an accurate BMR reading.

When researching your BMR you may also stumble upon the following related terms: Resting Metabolic Rate (RMR) and Resting Energy Expenditure (REE).

Always keep in mind that any BMR result is only a calculated guess. We all have a different metabolism and all respond differently to the activities we do. For example, one person may burn 100 calories on a 10 minute run, while the person running alongside may burn 150 calories.

Mifflin – St. Jeor Formula

The BMR equation, created by MD Mifflin and ST St. Jeor, in 1990, overshadowed most of the already existing prediction equations as soon as it was published. This new formula was found to be the most accurate yet.

Male: BMR = 10×weight + 6.25×height - 5×age + 5
Female: BMR = 10×weight + 6.25×height - 5×age – 161

These equations require the weight in kilograms, the height in centimeters, and the age in years.

Harris-Benedict Principle

This equation does not take into account calories burned during activities by large amounts of muscle mass, nor does it account for the additional calories supplied by excess body fat. Therefore, this equation will be most accurate in people with either a lean or normal body type.

Male
66.5 + (13.75 X weight) + (5.003 X height) - (6.775 X age)

Female
655.1 + (9.563 X weight) + (1.85 X height) - (4.676 X age)

These formulae also require the weight in kilograms, the height in centimeters, and the age in years

Using an online calculator

When using an online calculator, remember that you will have to factor in your physical activities. This means that your BMR will need to be multiplied by a number anywhere from 1.2 to 1.9.

The result will tell you tour maintenance calories, or the amount of calories you need to maintain your current weight. If you want to lose fat, you will have to subtract 20 per cent, or 40 per cent for extreme fat loss.

Just remember, whatever diet you decide on, make sure it is a healthy choice. Your body can only take so much change or abuse before it will start to react adversely.