A scale doesn't tell the whole story of your body composition. Figuring out your body fat percentage is incredibly helpful, but is something that can only be done accurately using a tool like an air displacement plethysmograph (Bod Pod). An alternative is using an online body fat calculator, which won't yield incredibly accurate results, but will give you a measurement by which to track your progress.
How to Use Online Body Fat Calculators
A body fat calculator is not the same as a BMI calculator. Any body fat calculator striving to offer the most accurate results possible will request not only your weight, but also some body measurements. This is because body weight consists of both fat and muscle, so weight alone isn't an accurate way to estimate body fat. Try one of the following body fat calculators available online to get a starting point measurement to track your progress.
Linear Software's Body Tracker can be used with either a fat caliper or a tape measure along with your weight and age. A fat caliper instrument can help give you more accurate results than a tape measure will, but if you use this method, get help from a fitness professional adept at using this tool. It can be tricky to use a caliper instrument properly on your own, especially in hard to reach places.
Active Body Fat Calculator
The Active body fat calculator requires your weight and various measurements. The results are gender-specific since women and men generally have different body shapes naturally. Results are then compared to a generalized graph which assigns categories (such as acceptable and obese) based on the calculator results. This calculator offers a good estimate which can be used as a basis of measurement to track your progress.
Health Status Calculator
The body fat calculator from Health Status uses the U.S. Navy method of body fat measurement - basically, the method used to measure body fat on sailors using a tape measure. After taking your measurements and entering your gender, weight, and height, the calculator will return an estimate of your body fat percentage. And while it will also give you a result for your BMI, it's important to note this number doesn't take into account fat versus muscle.
Jackson-Pollock Body Fat Calculator
Legion Athletics offers a body fat calculator based off the Jackson-Pollock method of measurement. You will need access to a caliper instrument to complete this calculator. Your age, weight, and gender are also required. While the Jackson-Pollock method sometimes uses seven caliper sites on your body, this calculator only uses three. The spots you measure depend on your gender.
YMCA Body Fat Calculator
The YMCA is a respected community fitness organization - BizCalcs' calculator utilizes the YMCA measurement method. This is one of the simplest calculators in that you don't need extra equipment (such as a caliper) and only need to supply your waist measurement (which most people know from buying pants), your gender, and your weight. The results will be estimates and may not be as accurate as a calculator requiring additional measurements, but if you simply want a starting point to track progress, this estimate will work.
How to Calculate Body Fat at Home
While online calculators can be useful tools for estimates, calculating your body fat at home doesn't require them. In fact, many tools are available that require no measuring whatsoever.
Scales and Handheld Instruments
Body fat scales and handheld body fat devices work by sending an electrical impulse through your body - how long that impulse takes to get back to the device depends on how much body fat you have. Though these instruments aren't as accurate as more expensive and time consuming methods (like hydrostatic measuring), they can give a good estimate for tracking body fat changes.
Caliper for Body Fat
A caliper instrument pinches body fat in different locations to help estimate body fat. These are excellent tools for tracking progress as you lose body fat.
Body Fat Changes
As you gain muscle and lose fat, the scale may not budge. That's why it's important to use other methods of measurement to track your progress. Take progress photos monthly to see how your body's composition changes though the scale doesn't indicate change.