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 Calculator
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.
Body Fat Calorie Burn Calculator
Are you curious to find out how long or how far you need to walk to burn off the calories in that doughnut you shouldn’t have eaten? Then, you may find this online calculator useful.
You can also use this calculator as a planning tool for weight loss from a regular physical activity.
Body Fat Percentage Calculator
Being overweight or obese from an excessive amount of body fat leads to increased morbidity and mortality risks. This is well established through numerous findings and 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 main contributor of excessive body fat is overeating. Research show that overeating can impair cognitive functions and impair memory. Mark P. Mattson of the Department of Neuroscience, Johns Hopkins University School of Medicine, recently published a paper giving an explanation on why overeating impairs cognition from an evolutionary perspective. Other laboratory studies explain the actual mechanisms at work in brain function impairment due to excessive body fat.
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 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 this online calculator together with a measuring tape or skinfold caliper, you can get a good estimate of your body fat percentage.
BMI for Adults Calculator
Body Mass Index (BMI) is commonly used as a preliminary diagnoses in identifying health risks associated with excessive or insufficient weight. It is a simple but useful numeric measurement of fatness or thinness that applies to the average population of average body composition. The index is based simply on a person's height and weight.
BMI is a good general purpose formula for the populace but it does not take body composition into consideration. It does not distinguish between weight due to muscle mass and that of fat mass. Since muscle tissue is denser than fat, it weighs more than fat on a comparative volume basis. Consequently, muscle builders and athletes may show a higher BMI than normal but may not be at all at a greater health risk. In contrast, children, while still growing and developing muscles and the elderly who may be losing muscle may show a lower BMI. Additionally, the body composition of pregnant or lactating women changes dramatically during these periods and so BMI cannot be considered applicable for them.
BMI also does not take body fat distribution into consideration. Studies have shown that excess abdominal fat can also contribute to higher health risks. Use the BMI calculator in conjunction with the other online calculators found on this site such as the Body Shape Index and Waist-to-Hip Ratio calculators for further assessment of your health risk status.
BMI for Child or Teen Calculator
Since 1980, the percentage of children who are obese has more than tripled in the U.S., from 5.5% to 17% and a similar trend is occurring worldwide. Overweight children are getting so prevalent that they are now perceived by some as normal. 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.
For adults, Body Mass Index (BMI) is commonly used as a preliminary diagnoses in identifying health risks associated with excessive weight. It is a simple but useful numeric measurement of fatness or thinness.
Excessive weight is evaluated differently for children and teens. Unlike BMI for adults, age and sex is taken into consideration because boys and girls grow at different rates and differ in their amount of body fat as they grow. Consequently, so does their relation to body fatness. For children between 2 and 20 years of age, BMI is calculated using the same formula as adults but their BMI is compared with growth charts. From the growth chart, a BMI percentile is produced from the child's BMI, age and sex. Their BMI is often referred to as BMI-for-age.
BMI-for-age percentile is a useful indicator of how your child’s weight compares with other children of the same age and sex. If for example, your child is in the 80th percentile, it means that your child’s weight is greater than that of 80% of the other children of the same age and sex.
This calculator first calculates your child's BMI then looks up the corresponding BMI-for-age percentile for your child's sex and age. The percentile is derived from the Centers for Disease Control and Prevention growth charts data.
Basal Metabolic Rate Calculator
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 in a temperate and neutral environment for an entire 24 hour period of time.
This calculator uses the Mifflin-St Jeor equation which is a predictive equation derived from statistical data.
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 composition (ratios of lean body mass to body fat) differ between men and women. A women's BMR is typically 5 to 10% lower than man's.
Body Weight Planner Calculator
Use this app as a body weight planner or weight loss calculator. If your plan is to reach a target weight within a certain time frame, the calculator can tell you the amount of food energy or calories you would need to consume on a daily basis to reach it. Alternatively, you can specify a daily dietary energy intake that's workable for you and it will calculate how long it would take to reach your goal weight.
A change in body weight results from the difference between your food energy intake and the amount of energy expended by your body. Energy is burned in maintaining your body functions and in performing physical activities. For successful weight loss to occur, there must be an energy imbalance such that energy expenditure is greater than your energy intake.
There is a widespread myth that by reducing your energy intake by about 500 Calories (2.1 MJ) per day, you will slowly lose about 1 lb (0.45 kg) of weight a week. The National Institutes of Health and the American Dietetic Association have both erroneously stated this. This rule is sometimes referred to as the 3500 Calories per pound rule and is used in many weight loss formulas. It is overly simplistic and it's accuracy can be called into question especially in the long term.
The rule's inaccuracy stems from the fact that it does not take into account the physiological changes that occur during weight loss, your sex, age and initial weight. The amounts of body fat and lean tissue both change with an energy imbalance. Pound for pound, the energy content of body fat is about 5 times that of lean tissue. When you reduce your energy intake, muscle mass is lost along with fat mass. This reduces your resting metabolic rate, causing you to burn less energy.
As an example, if you were to take in 500 less calories a day (3500 Calories a week), you would lose 1 lb a week according to the rule. So if you were planning on losing say 25 lbs, it would take you (25 x 1) or 25 weeks to do so. This is clearly wrong. According to the model developed by Kevin Hall, Ph. D., and a team of researchers at the National Institute of Health, it would actually take over 37 weeks if you were a 34 year old, 6 foot sedentary male initially weighing 250 lbs. Actual times would vary somewhat depending on sex, age, height and initial weight.
Estimated Energy Requirement Calculator
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.
This calculator uses the Institute of Medicine equations to calculate EER. It covers all age groups, as well as pregnant and nursing mothers.
Realistic Weight Loss Goal Calculator
How much weight is realistic for you to lose and how many calories or kilojoules should you be consuming?
Use this calculator to find a realistic weight loss energy deficit plan that's right for you. You choose how much you want to weigh. The calculator will generate a table that lists daily energy intakes along with the maximum time it would take you to reach your weight goal for each of the food energy intake levels.
Waist-To-Hip Ratio Calculator
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.