This calculator uses the U.S. Army's 2023 one-site tape method to estimate body fat from just your weight and abdominal circumference, then checks the result against the AR 600-9 maximum for your age and sex. It's the same approach used in the Army Body Composition Program after the ALARACT 046/2023 update.
Formula
The one-site equations use body weight in pounds and abdominal circumference in inches:
Men: %body fat = -26.97 - (0.12 × weight) + (1.99 × abdomen)
Women: %body fat = -9.15 - (0.015 × weight) + (1.27 × abdomen)
The result is rounded to a whole percent and compared with the maximum allowed for your age group.
Maximum allowable body fat (AR 600-9)
| Age group | Male | Female |
|---|---|---|
| 17–20 | 20% | 30% |
| 21–27 | 22% | 32% |
| 28–39 | 24% | 34% |
| 40+ | 26% | 36% |
Examples
Male, age 25, 180 lb, 34 in waist
%fat = -26.97 - 0.12 × 180 + 1.99 × 34 = -26.97 - 21.6 + 67.66 ≈ 19%. The limit for a 25-year-old man is 22%, so this is within standard by 3%.
Female, age 30, 140 lb, 30 in waist
%fat = -9.15 - 0.015 × 140 + 1.27 × 30 = -9.15 - 2.1 + 38.1 ≈ 27%. The limit for a 30-year-old woman is 34%, so this is within standard by 7%.