Why do you need to know about the different ways to measure body fat?
And why do you need to know your body fat percentage anyway? Find the answers to these questions here, along with the 5 simplest ways to measure body fat percentage.
Before anything else, you should know that your weight as a number alone doesn't tell you how much of your weight is fat and how much is muscle mass, which is heavier than fat.
So if your weight increases because you’ve worked out and gained lean muscle mass it's all good - as long as your body fat percentage diminished.
That’s why you absolutely need to determine your body fat percentage if you want to lose body fat rather than muscle mass and/or water.
If you've read the good body fat percentage page, you've seen that - depending on your age - a healthy body fat percentage is between 19-31% if you are a woman, and between 11-23% if you are a man.
For example, if you’re a young woman weighting 180 lbs and your body fat percentage is 35%, it means that you have 63 pounds of fat... You should aim to reduce this to approx 45 pounds, which represents a healthy body fat percentage of 25%.
So here’s how to measure body fat.
There are five main types of methods to measure body fat, shown in order of practicality:
These ways to measure body fat are increasingly accurate but less practical (and less affordable) as you go down the list. You may not have access to a hydro-densitometer in a water tank.
And, you may not afford to get a CT scan just to find out your body fat percentage.
So the last two methods listed may or may not be for you, but you should know about all the options available.
And there's one more thing to consider.
Depending on how conditioned your body is, hence how much body fat you have, the method you use to measure your fat percentage should be increasingly accurate.
For example, if you exercise a lot and have a muscular body, use the skinfold test for a more accurate measurement of your body fat percentage.
On the contrary, if you haven't exercised in years (or never in your life), you are better off measuring your waist-to-hip ratio (especially if you're a woman).
Or, go with an even simpler way to determine how much over your normal weight you are relative to your height, using the BMI (Body Mass Index).
Then, as you start to exercise regularly and your body composition changes, so does the way you measure it. So, when it comes to the different ways to measure body fat, the most important thing is to go with what's most appropriate for you NOW.
Let's get down to it.
1. Waist-to-Hip Ratio (WHR) is the simplest circumference method of measuring your body fat that gives you a ballpark figure rather than an exact body fat percentage. This simplest method estimates your body fat, telling you whether you have an apple body shape or a pear shape body.
Measure your waist at the narrowest point and your hips at the widest point. Hold the tape loosely, without applying pressure on your skin, and stand up straight, relaxed, and without sucking in your tummy.
Next, divide your waist number by your hip number. If the result is:
2. Skinfold Testing is another convenient, do-it-at-home method, the most common of all ways to measure body fat. Skinfold testing provides great consistency over repeated measurements and you can do it with a skinfold caliper, like Accu-Measure, for example.
Skinfold testing is based on the fact that you store most of your body fat directly under your skin - subcutaneous fat. You can determine your overall body fat percentage very accurately by grasping the skin and underlying tissue, shaking it to exclude any muscle and pinching it between the jaws of the caliper.
3. BIA (Bioelectric Impedance Analysis) Body Fat Scales (or hand grippers) determine the percentage of your body fat by passing a low-intensity electrical current through your body and measuring its electrical conductivity. Fat is less conductive because of its low water content.
Although highly marketed, sadly, BIA testing gives you inconsistent results at different times, as your body’s water content fluctuates greatly throughout the day. To get an accurate result, you must not eat, drink or exercise several hours before the test. Even drinking coffee and alcohol, which dehydrate your body, must be avoided prior to this test.
4. Underwater Weighing is considered the most accurate (although highly impractical) among all the ways of measuring body fat.
Underwater weighing is based on Archimede’s Principle, or the Law of Buoyancy, which explains why submerged things stay afloat: "any object, wholly or partly immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object".
Since fat is lighter than water, the more fat you have, the more you will float. By measuring the amount of water you displace when immersed, a technician calculates your body density; then, based on this, a formula is used to calculate your body fat.
If the thought of being dunked with all the air blown out of your lungs in a water tank sitting on a chair that hangs from a scale appeals to you, go for it.
5. CT Scans are very accurate (although expensive) ways to measure body fat. Also called Dual Energy X-ray Absorptiometry (DXA), this test uses a whole body scanner and two different low-dose x-rays to read bone mass and soft tissue mass.
Particularly useful in giving a ratio of visceral fat to subcutaneous fat, this test measures not only your body fat percentage with a 1-3% error margin, but your bone density too. However, the cost of this method is prohibitive for most people like you and me.
If you are like most people visiting this site, you are interested mostly in getting rid of flabby fat and getting into shape, rather than getting a ripped set of abdominals. If that’s the case, the best ways to measure body fat are the first two on the list above, the waist-to-hip ratio (WHR) and skinfold testing. Or, you can use a body fat index calculator.
Regardless of the method used, once you know the percentage of body fat you have, you can determine where you stand by checking the body fat percentage chart.