The following calculator gives you an estimate of your % bodyfat and lean body mass based on your weight, height, age and simple tape measurements (i.e. anthropometric measurements). Skin-fold measurements alone tend to underestimate body fat percentage in the obese and very lean (particularly with low hydration levels). The following calculator is based on equations which are useful for people in these groups as well as people with loose skin after very large weight loses. It is generally accurate to within a few percent. Anecdotally, it has also proven to be reasonably accurate with drug-free, genetically typical bodybuilders.
- Age – your age in years
- Height – your height without shoes
- Waist size – measure around your waist at your navel and also at the point midway between your navel and the bottom of your sternum, and take the average of these two measurements – that is your “Waist” measurement. Stand tall, but do not deliberately suck in your stomach or the estimation will be wrong.
- Iliac – measure around where your upper pelvic bones protrude the most (you can feel for them on either side of your waist/hips)
- Hips – measure around the hips at the maximum protrusion of the buttocks
How to measure the body fat percentage?
Undoubtedly, determining body fat percentage is not an easy task! A weight lifter and an obese person may have the same weight, but their body fat percentages are different. Remember, weight alone does not tell you how much muscle or fat you have.
Read this post to learn more about different methods for determining your body fat percentage.
The easiest and most common method for measuring body fat percentage is to use a soft tape measure. You can purchase body fat measuring tapes in the market. For this method, a person should know his height in inches.
If you are a man, then you should measure the circumference of your neck and abdomen. Make sure that you measure the largest part of both the areas. Also, the task will be easier if you have a friend or family member help you.
To find the body fat percentage, you just need to subtract the value for the neck from the value for the abdomen to get the value for the circumference.
If you are a woman, you will need to measure the circumference of your natural waist, neck and hips. Again, you will need to measure each area at its widest point. Ask your friend or a family member for help.
7 Ways to Measure Body Fat
There are many ways to estimate body fat. These methods use a wide variety of technologies, ranging from very simple (a tape measure) to very complicated (three-dimensional laser scanning technology. Each method has pros and cons and different levels of accuracy. Here is a quick review of those major technologies.
One of the most readily accessible ways to estimate body fat is to measure the physical thickness of the adipose (fat) layer directly under the skin. This layer is known as the subcutaneous fat layer. This method relies on precisely built and calibrated calipers that measure skin thickness in millimeters. While easy to perform, this method requires a substantial amount of training and has a pretty high error rate, with up to 10-15% error rates reported in some studies. As such, it is difficult to be certain of changes of <5% of body fat.
Another very accessible and easy to perform method of estimating body composition is through measuring body circumference. More specifically things such as waist-to-hip ratios, waist-to-height ratios, and neck circumferences are ways to estimate body composition. There are good data to show how well different measures correlate to body fat percentages. Interestingly, waist to weight ratio appears to be the most accurate.
Hydrostatic weighing, also known as underwater weighing, is one of the more accurate forms of body composition assessment with error rates being between 2-5% for most apparatuses. However, this approach is expensive and requires very specialized equipment and training. For most people, this form of body composition assessment is impractical.
Bioelectrical impedance analysis, often referred to as BIA, utilizes electrical currents to assess body composition based on how electrical currents flow through the body. This method is very readily available as it can be put into handheld devices and even at home digital weight scales. However, many of the low-cost commercial models are imprecise with large error rates (greater than 10%). Research grade devices can have error rates as low as 5%.
Air-displacement plethysmography utilizes a similar principle as hydrostatic weighing, displacement. However, instead of displacing water, this method displaces air. It is roughly similar in terms of accuracy as hydrostatic weighing (hydrostatic weighing is slightly more accurate) but is substantially cheaper and easier to perform. The Bod Pod® is the most used device.
3D Body Scan
A new, emerging technology that is becoming more readily available are three-dimensional (3D) body scans. These technologies utilize laser capture technology to measure anthropometrics and estimate body composition. These technologies show relatively similar accuracy to other measures such as bioelectrical impedance, hydrostatic weighing, and air-displacement plethysmography with error rates between 3-10% depending on the instrument used.
Dual Energy X-ray Absorptiometry
Dual Energy X-ray Absorptiometry, commonly referred to as DEXA (DEXA) utilizes specialized machines that have different types of X-rays which can measure differences in density of tissue. This approach requires very specialized equipment and training, and some-states require licensure to use DEXA technology due to the radiographic nature of the equipment. While often believed to be the most accurate method of estimating body fat percentage, DEXA is roughly equal to air-displacement plethysmography, hydrostatic weighing, and 3D body scanning technology.