I cannot find a metric formula to calculate body fat composition.

Is there any right and valid metric formula for body fat calculation?

5 Answers 5


Your best bet for a body fat measurement if you want pure metric, is to find someone local that is well trained in using body fat calipers. They measure in millimeters, and the formulas calculate out using that as a basis.

However, any body fat measurement produces a percentage number. The math ahead of time is just numbers in a formula, it shouldn't matter unless you have absolutely no way to measure in inches. Once you have that number, you just apply it to your weight in kilograms instead of pounds.


If, for example, you wanted to use the "Navy" body fat calculation formula:

  1. Measure the circumference of your waist at a horizontal level around the navel for men, and at the level with the least width for women. Don't pull your stomach in.
  2. Measure the circumference of the neck. Start below the larynx with the tape sloping slightly downward to the front. Avoid flaring your neck out. For women only: Measure the circumference of the hips, at the largest horizontal measure.

body fat calculator formula for man: 495/(1.0324-0.19077(LOG(waist-neck))+0.15456(LOG(height)))-450

body fat calculator formula for woman: 495/(1.29579-0.35004(LOG(waist+hip-neck))+0.22100(LOG(height)))-450

All you'd have to do, is convert centimeters into inches (inches = centimeters / 2.54) and use those values in those equations...or just use the calculator here (just switch it over to the "metric" tab)

Hope this is what you're looking for.

  • I know this formula, as mentioned here: wikihow.com/Measure-Body-Fat-Using-the-US-Navy-Method I wanna measure it by metric values and the ones here Are not valid. Apr 27, 2015 at 11:35
  • when I myself calculate it, it returns -25!!! Apr 27, 2015 at 11:47
  • Clarifying comment - Circumference measurement is one of the least accurate measurement techniques. And converting from metric to inches introduces another conversion layer that can be misdone.
    – JohnP
    Apr 27, 2015 at 16:35

I used the formula found in the link bellow which is for imperial system, but with some calculations you can adapt it to metric system.


Imperial system formula:

Lean Body Mass = (Total body weight x 1.082) + 94.42 - (Waist measurement x 4.15)

Metric system formula:

Lean Body Mass = (Total body weight x 1.082) + 42.83 - (Waist measurement x 0.74)


Total weight: 80kg/176pounds

Waist: 88cm/34.5inches

Body Fat = 19% (in both formulas)

Also you can check your results with the website which provided formula.


(you can ignore values for wrist, hips and forearm; just put something)


There are some body fat formulas that estimates body fat with BMI

  • Deurenberg Formula
  • Deurenberg Formula #2
  • Gallagher Formula
  • Jackson-Pollock Formula

At this page (first column, fourth choice) is a "body fat test". The estimated body fat is calculated using all 4 formulas.

Link: Assessment Tests

On the result page is a tape measurement calculator. This is a very accurate body fat calculator. I was test by Prevention Magazine comparing it against the Skin Fold Caliper to the Hydrostatic Weighing Method.

Prevention Magazine said this calculator was more accurate than the Skin Fold Caliper and matched the results from the Hydrostatic method.

It is not a formula though. I wrote the code back in 1993 and did the Web version in May 1996. The tape measurements it asks for change for male and female, an age above 27 or below 28 years old.

This website was never promoted commercially and was abandoned about 10 years ago. But the Body Fat Calculator still works just fine.

Not sure why you need a formula, but if you need a metric version I could make you one.

I pulled the 4 BMI formulas out of this page.

  $FatBMI  = (1.2  * $BMI) + (.23 * $age) - 5.4;
  $FatBMI2 = (1.29 * $BMI) + (.20 * $age) - 8;
  $FatBMI3 = (1.46 * $BMI) + (.14 * $age) - 10;
  $FatBMI4 = (1.61 * $BMI) + (.13 * $age) - 13.9;
  • 1
    Relying on BMI alone is problematic, particularly if you don't fall into the "normal" population. Among people who perform strength training and have higher than average lean mass, BMI becomes useless rather quickly. Apr 27, 2015 at 20:27
  • @BerinLoritsch And that is why I do not use BMI. My method is based on a paper written by Catch and McCardle years ago. Prevention magazine found my approach to compare to Hydrostatic Weighing by saying "Bullseye". But it is not a simple formula, just a lot of programming code and some luck. The BMI is used by me for reference purposes. Apr 27, 2015 at 21:05
  • I'm familiar with Katch-McCardle for estimating BMR, which is what I use, since it references lean mass. I wasn't aware they had a body fat estimation formula (doctorholmes.wordpress.com/2011/02/10/…) Apr 27, 2015 at 21:13
  • 1
    @BerinLoritsch They don't. I created my own based on their paper that was written before the advent of the PC. I use the BMI just in case some one mistakenly enters the wrong value. It is based on tape various measurements for age (27 and less/28+) and gender. I have an abandoned website where I created a calculator in May of 1998. Originally tested by Prevention Magazine as a DOS app in 1995. Apr 27, 2015 at 21:19

Personally I use the BioMetrIcs Android app to calculate / review the formula of a dozen of the more common estimates, but the BiranMac site is a good reference for most of the fitness related formula:

  • Cannot download it. Apr 28, 2015 at 9:16

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