Body Fat Calculators
Welcome to Body Fat Calculators. This site contains various online calculators for you to use as self-help tools in managing your weight and achieving healthy weight goals. Click on any of the cards below to open up a calculator for the type of calculation you wish to perform.
The main theme of this app is body fat, an excess of which could lead to diabetes, hypertension and coronary artery disease. Use these online calculators, together with a weigh scale, measuring tape and/or calipers, to make a personal assessment of your health risk status.
A Body Shape Index
Body Mass Index, or BMI, is a familiar term to many. It's a formula that compares your weight to height. There are numerous online calculators, including one on this site, that allow you to plug in your weight and height values and calculate a BMI number for you.
BMI has a major flaw. It doesn't tell you anything about where you’re carrying your weight. Numerous studies have found that being apple shaped or carrying excess belly fat is riskier than having a heavy bottom or being pear shaped.
To address this limitation, City College of New York researchers developed a new formula they call A Body Shape Index or ABSI. Index values were calculated on a US sample of over 14,000 non-pregnant adults. The numbers were then compared to the mortality rates for the same group. They found that high death rates were correlated with both low and high BMI, but ABSI predicted premature death from all causes and regardless of other factors like age, sex, ethnicity and lifestyle choices.
The study concludes that even though you may have a normal BMI, you may be at a greater risk of dying sooner if you carry excessive weight in your midsection relative to your height and weight.
Being overweight or obese from an excessive amount of body fat leads to increased morbidity and mortality risks. This is a well established fact and numerous findings show that your body weight alone is not always a good indicator for these risks. It's important to know your body composition; how much of your weight is due to body fat and how much of it is in the form of lean body mass.
The amount of body fat is usually expressed in terms of a percentage of overall weight. Once you know your body fat percentage, you can refer to the body fat charts and tables developed by health and fitness organizations to help you achieve a healthy body fat.
Although there are a number of different techniques that can accurately measure your percentage of body fat, they can be expensive and inconvenient. Using the online calculator available on this site, together with a measuring tape or skinfold caliper, you can get a good estimate of your body fat percentage.
Body Mass Index
Body Mass Index (BMI) is a person's weight in kilograms divided by the square of height in meters. It is commonly used as an easy and quick screening tool to identify health risks due to excessive or insufficient weight. It is a simple but useful measurement of fatness for an average adult between the ages of 20 and 65 years.
Although BMI does not measure body fat directly, there is a strong correlation between BMI measurements and the more direct approaches to measuring body fat. These include underwater weighing, skinfold thickness, impedance measurements and many others.
BMI is not appropriate for athletes, pregnant or nursing women and the elderly. For people with muscular builds, it may overestimate body fat. For the frail and elderly, it may underestimate body fat.
Body Mass Index for Children and Teens
According to the American Heart Association, nearly 1 in 3 children or teens in the U.S. are overweight or obese. That's a 3-fold increase since 1963. The extra weight can pose significant health risks during the development years and into adulthood. There is an 80 % chance that they may stay overweight for their entire lives.
BMI is age and sex specific for children and teenagers and is often referred to as BMI-For-Age. A child's weight and height changes during growth and development. Correspondingly, so does their relation to body fatness.
The calculator available on this site calculates BMI and then expresses it as a percentile relative to other children of the same sex and age. These percentiles are calculated from the Centers for Disease Control and Prevention growth charts.
Basal Metabolic Rate
Your BMR (Basal Metabolic Rate) is the minimum amount of energy your body requires to support the body's autonomic systems such as breathing, digestion, the nervous system, circulation, and regulation of body temperature. It can be used as an estimation of how much energy your body would burn if all you did was rest or sleep in a temperate and neutral environment for an entire 24 hour period of time.
Factors that affect your BMR include age, genetics, weight, heredity, body fat percentage and gender. Knowing your BMR, and the factors that affect your metabolism, can help you with your goal to lose, gain or maintain your current weight.
Your BMR decreases with age because your muscle mass declines, so it becomes harder to stay trim.
Weight and height affects your BMR. The bigger you are, the more energy you need to sustain your larger organs. If you lose weight, your BMR goes down because you require less energy. On the other hand, if you build up your muscles, your BMR increases.
Body Weight Planner
Calculate the amount of food energy you need to consume on a daily basis to reach a weight goal within a desired period of time.
The calculator incorporated into this app is based on a model developed by Kevin Hall, Ph. D., and a team of researchers at the National Institute of Health. It is a much more accurate model in determining energy expenditure and energy requirements for the purpose of weight management. It challenges the commonly held belief that eating 3,500 fewer calories or burning off that equivalent amount of energy through exercise will always result in a pound of weight loss.
Estimated Energy Requirements
Estimated Energy Requirement (EER) is an estimate of the average amount of food energy you need daily to balance out your body's expenditure of energy in order to maintain body size and composition at a level of physical activity consistent with long term good health.
Energy intakes above the EER would be expected to result in weight gain, whereas intakes below the EER would be expected to lead to weight loss.
The online calculator uses the Institute of Medicine equations to calculate EER. It covers all age groups, as well as pregnant and nursing mothers.
Waist to Hip Ratio
The amount of fat, but more importantly, where in your body that fat is stored can impact your health. If you have most of the body fat around the waist, you have an increased risk of high blood pressure, heart disease, diabetes and stroke compared with having the same amount of body fat around the hips and thighs.
A common measure of fat distribution is the waist-to-hip (WTH) ratio. It is calculated by dividing the circumference of your waist by the circumference of your hips.
The waist-to-hip ratio, in some case, can be a better indicator of mortality risks than body mass index (BMI). You could possibly have too large of a waist, even though your BMI indicates a healthy weight. On the other hand, if you are muscular, a BMI may indicate an unhealthy weight.