There are now quite a few online weight loss calculators on the web. These calculators allow you to calculate a number of pieces of information relevant to a weight loss process. In this article I will detail some of the information that such calculators may return.
Some of the metrics that are calculated by these calculators include:
Your BMI: Your BMI, or body mass index is a metric that is commonly used to give an estimate of whether you are overweight for your height. To calculate your BMI, you simply need to input your wight and your height. A calculator can then return your BMI. There are different ranges for this BMI that give an indication as to whether a person may be severely underweight, underweight, normal weight, overweight or obese. This metric does have limitations as it does not consider your body fat percentage, but is however commonly used as a metric to help determine your weight range.
Your BMR: Your basal metabolic rate (BMR) is more or less an estimate of the number of calories you burn a day while at rest with no digestion occurring. BMR calculators can calculate your BMR from a variety of methods. Two of the most commonly used methods here are the Harris Benedict equations and the formula of MD Mifflin and ST St Jeor. Both of these methods allow an estimate of your BMR to be computed by inputting you height, weight, age and gender.
The calories you burn a day: One of the most relevant pieces of information a weight loss calculator can compute is an estimate of the calories you burn a day. By understanding the calories you burn a day, you are able to plan a diet around introducing a mild calorie deficit that should result in consistent weight loss until you reach a healthy weight. A common method to estimate the calories you burn a day is to first calculate an estimate of your BMR as detailed above and then adjust this BMR estimate to give an approximation of the calories you burn a day. This can be achieved by multiplying your BMR by a factor that is dependent on your activity level.
Recommendations as to your calorie consumption to lose weight: Once an estimate of the calories you burn a day has been computed, you can then use this to calculate various suggestions as to the calories you should consume to lose weight if you are overweight. For example, many sources recommend that to achieve consistent long term weight loss, you should aim to lose around 1 to 2 lbs per week. Creating a total calorie deficit of 3500 calories should result in about 1 lb of weight loss. This then means that if you introduce a calorie deficit of about 500 calories a day, you my lose 1lb of weight a week. A weight loss calculator that can compute the calories you burn a day, could for example subtract 500 calories from this and advise that consuming that many calories will result in about 1lb of weight loss a week.
While there are a range of other metrics weight loss calculators can compute, these are probably some of the most relevant and more common.