Body fat percentage (BF%) is pretty self explanatory, it’s simply the percentage of fat on your body.
Many trainers like to track their BF% during fat loss as a measure of progress, but getting reliable results can be tricky.
Read on to find out how much body fat you should have, and the best ways to calculate it.
How much fat should I have?
According to the American Council on Exercise, body fat ranges for adults are as follows:
How much fat do I have?
Short of cutting a body open, there is no foolproof way of knowing the exact amount of fat it contains. Fortunately, there are some less intrusive ways of getting an indication of where you stand in the fat stakes.
Some methods, like hydrostatic weighing, require access to a special water tank and a team of scientists, but the following techniques for estimating body fat, can be done at home, or by your local gym or GP.
1. Body mass index (BMI)
2. Bioelectric scales
3. Skin-fold calipers
4. Measurement method
Body mass index
This is the most commonly used body fat indicator. Simply divide your weight in kilograms by the square of your height in metres. The result is your BMI. You can use the chart above to plot your BMI. Those with a BMI over 25 are classed as overweight. Higher than 30, and you’re one of the 26% of adults in England who are obese.
BMI is a good rule of thumb indicator, but it won’t tell you how much fat your body contains. BMI doesn’t take account of bone density or how much lean muscle mass you have.
A fit, muscular rugby player might have a BMI that would classify them as overweight or obese, when in fact they’re not. For most of us though, it’s a reasonable pointer to being over or underweight.
To convert BMI to estimated body fat, work through the following formula:
(Where male = 1, female = 0)
Readily available to buy, many modern electonric bathroom scales can also give you a body fat percentage.
They work by passing a small electrical current through your body. Because lean muscle mass contains more water than fat, it’s a better conductor
The scales work by calculating total body water (TBW). TBW is used to estimate total fat free body mass.
This is compared with your overall body mass. The result is the amount of fat your body contains. If using this method to calculate your body fat, be sure to follow the manufacturer’s directions closely.
That’s because factors like dehydration, and when you last ate or exercised can affect the accuracy of the reading
A pair of calipers is used to measure the thickness of folds of skin pinched at specific sites on your body. The thicker the fold, the more fat it contains.
By extrapolating from the measurements you take, an estimated body fat figure is given.
The skinfold method can prove inaccurate unless the measurements are taken in exactly the right place each time. The type of calipers used can also affect the outcome of the test.
There are several methods for estimating body fat based on measuring your body. The U.S. Navy circumference method is one example. The equation compares the circumference of your hips, waist, and neck with your height and weight.
Essentially, you’re calculating the density of your body:
Estimated body fat is extrapolated from this result, but it’s not a very accurate measure.
So there you have it, four ways to work out your BF%! Let us know your favourite method in the comments below.