Body fat for females aged 70 to 79
Body fat can be estimated without special equipment. This page uses the Navy formula for a woman in her 70s with a 33 inch waist, a 39.5 inch hip and a 13.75 inch neck at 5 ft 4 in.
How it works
Body fat percent for females equals 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387, with all lengths in inches. The page converts centimeters for you. This female page uses 64 inches for height, 33 for the waist and 13.75 for the neck.
Worked example
For a woman in her 70s at 5 ft 4 in the measurements are a 33 inch waist, a 39.5 inch hip and a 13.75 inch neck. Waist plus hip minus neck is 58.75 inches. Its base 10 log is 1.76901, and times 163.205 that is 288.711. The height of 64 inches has a base 10 log of 1.80618, and times 97.684 that is 176.435. Subtract and adjust: 288.711 − 176.435 − 78.387 = 33.89. The estimate is 33.9 percent body fat, in the obesity range.
Common questions
How accurate is the Navy method?
It is an estimate. It is usually within a few percentage points of more precise methods, and careful measuring matters. For a woman in her 70s at 5 ft 4 in, a reading of 33.9 percent could be a few points higher or lower in practice.
Where do I place the tape?
Measure the neck just below the larynx. For men measure the waist at the navel. For women measure the waist at its narrowest point and the hips at their widest. Keep the tape snug and level without squeezing. For a woman in her 70s at 5 ft 4 in the waist number is 33 inches and the neck number is 13.75 inches.
Does age change the result?
The formula does not use age. The same measurements give the same estimate at any age. A woman in her 70s at 5 ft 4 in with a 33 inch waist, a 39.5 inch hip and a 13.75 inch neck gets 33.9 percent.
What is a healthy body fat percentage?
Ranges depend on sex and goals. The American Council on Exercise lists essential fat, athletes, fitness, average and obesity ranges. At 33.9 percent, a woman in her 70s at 5 ft 4 in falls in the obesity range, which spans 32 or more percent.
Why does the waist matter more than weight?
Waist size reflects fat carried around the middle, while body weight cannot tell fat from muscle. For a woman in her 70s, a waist of 33 inches against a height of 64 inches gives a waist-to-height ratio of 0.52.