The other day I mentioned that I calculated my body fat percentage using a formula I found at You enter your weight and your waist circumference measured at the navel (for men – women can also calculate but have a few more variables to measure) and it spits out a number accurate to +/- 3%.  Now I recall that in the Army we would measure BF% using waist and neck measurements.  So today I thought I would run my numbers through a couple different online calculators to compare the results.

Usually I just wrap a tape measure around my waist and record the number but I wanted to be more accurate this time, so I actually stood in front of a full length mirror and ensured that the tape was straight all the way around.  Here are the numbers:

Height – 5′ 10.5″

Weight – 190.7 lbs

Waist – 36.5″ (measured at navel)

Hips – 41.5″ (measured around the buttocks)

Neck – 16.5″ (measured below the larynx)

Chest – 45.5″ (at the nips – this one was difficult, so may be off a little)

Biceps – 14.5″

Forearm – 12″

Wrist – 7″

First up is the calculator. All it needs is weight and waist.

Result = 21.72%

(If you don’t want to mess with Excel, there is an online calculator which uses the same formula here.)

The next calculator is from This one uses both Army/Navy and YMCA developed formulae, and requires 2 waist measures, hips, neck, height, and weight.  The only thing I dislike about this calculator is that the height is entered by a drop-down menu, so I had to pick either 5′ 10″ or 5′ 11″.  I did both.

Result @ 5′ 10″:

19.32% Army/Navy   19.62% YMCA = 19.47% average

Result @ 5′ 11″:

18.89% Army/Navy   19.62% YMCA = 19.25% average

Total Average = 19.36% provided the next one, using a Navy formula.  I like this one because I could put my actual height. It asks for height, weight waist, neck, and activity level.  It not only provides BF%, but calculates lean mass, BMI, waist-to-height ratio, and gives caloric and protein recommendations.

Result = 19.1% (probably why I like it so much, hehe)

Lastly, there is this calculator from A bit more in-depth, this one asks for age, weight, waist, hips, forearm, and wrist, as well as calculating lean mass.  Sadly, this site does not allow you to input decimals, so I had to run it twice, first rounding the .5 values up then rounding down. I used 191 for both weights.

Rounded up = 18.6%

Rounded down = 17.1%

Average = 17.85%

Average of All Calculations = 19.50% Body Fat

Average Fat Poundage = 37.2 lbs

Average Lean Mass = 153.5 lbs

Average American Male = 22% Body Fat

Healthy Normal = 15% Body Fat

Using this calculation from, I can determine that my weight at 15% body fat should be 180.2 lbs.  Of course that assumes no lean mass losses or gains.

So to sum it up, body fat calculations can vary quite a bit depending on the method used.  I personally prefer the mirror, but these calculators are useful tools to track monthly progress, and to make sure you aren’t losing muscle during strict dieting.

What say you?!