Body fat calculator and fat free mass index FFMI

If you want to find out how much of your total body mass is fat, you can find this out using measuring tape. If you have a scale with a body fat measurement feature, the process becomes even easier.

The fat free mass index is calculated at the same time. FFMI is a measurement of your body’s muscle makeup. It is derived from your height, weight and percentage-based body fat level.

Imperial Metric

Body fat / FFMI calculator for women

Height: feet / inches
Neck circumference: feet / inches
Hip circumference:: feet / inches
Waist circumference: feet / inches
Weight: lb

Body fat / FFMI calculator for men

Height: feet / inches
Neck circumference: feet / inches
Belly circumference: feet / inches
Weight: lb

You can use various further methods to measure your body fat percentage. In practice, the value is often determined using a caliper to measure the thickness of your skin folds. However, this method does not allow you to measure organ fat. Still, it gives you a good picture of overall fat percentage. The advantage of non-electric measuring methods is that coffee and alcohol do not change your measurements.

You can measure yourself both before and after exercise, as the fat tissue underneath the skin does not change quickly. However, a temporary change in water weight, for example after physical exertion or a trip to the sauna, can influence measurement.

Measurement of body fat percentage with a body fat scale as well as bioelectrical impedance analysis (BIA) is another common method. There are also body fat scales that measure your organ fat percentage and bone mass.

You should take age, sex and body type into consideration when thinking about what percentage of body fat is healthy. Body fat percentage increases as you age, the lean mass percentage dropping due to muscle mass decreasing as you get older. For men around the age of 45, a body fat percentage of 22-24% is normal, with about 30% typical for women of the same age. In general, women have a higher body fat percentage, as they need larger fat reserves during pregnancy and while nursing.

Age Women (in %)
low normal high very high
20–39 < 21 21–33 33–39 ≥ 39
40–59 < 23 23–34 34–40 ≥ 40
60–79 < 24 24–36 36–42 ≥ 42

Age Men (in %)
low normal high very high
20–39 < 8 8–20 20–25 ≥ 25
40–59 < 11 11–22 22–28 ≥ 28
60–79 < 13 13–25 25–30 ≥ 30

For professional athletes up to the age of 30, you will usually find even lower body fat percentages. A male professional bodybuilder will have a body fat percentage of around 5% during competition season. Whether this is healthy is another question. Men need a minimum amount of 2-5% body fat to survive, while women need between 10-13%.