Suprisingly Accurate Bodyfat Calculation
 05232006, 12:44 PM
Suprisingly Accurate Bodyfat Calculation
I found this on Dave Draper's site:
http://davedraper.com/bodyfatcalculation.html
For Men:
Before you use the formulas, there are two measurements that are required:
Measurement 1: Bodyweight
Measurement 2: Waist Girth (measured at the umbilicus)
Procedure:
1) Multiply your bodyweight by 1.082. Add the result to 94.42. Once your calculation is complete, save the number. à (Bodyweight x 1.082) + 94.42=Result 1
2) Multiply your waist girth by 4.15. Once you get this result, subtract it from the number obtained in step 1 (ie: Step 1 resultStep 2 result). The result obtained after the subtraction is done is your lean bodyweight (your weight if you had no fat in your body at all). à Result 1  (Waist Girth x 4.15)= Lean Body Weight
3) Finally, subtract your lean bodyweight from your total bodyweight (Total weightLean Bodyweight). Once you get the result, multiply that number by 100. Once you get the result divide it by your total bodyweight. This final result is your percentage of body fat. à ((Total Bodyweight  Lean Bodyweight) x 100) divided by (Your Body Weight) = Your Percentage of Body Fat.
Example:
I weigh 190 and I have a 30.5inch waist. Therefore, step 1 is (190 x 1.082) + 94.42 = 300. Step 2 says that my lean body weight equals 300(30.5 x 4.15)=173.425. Finally, Step 3 says that my body fat percentage is ((190173.425) x 100) divided by 190= 8.72%.
For Women:
Before you use the formulas, there are five measurements that are required:
Measurement 1: Bodyweight.
Measurement 2: Wrist Circumference (measured at the widest point).
Measurement 3: Waist Circumference (measured at your umbilicus).
Measurement 4: Hip Circumference (measured at the widest point).
Measurement 5: Forearm Circumference (measured at the widest point).
Procedure:
1) Multiply your bodyweight by 0.732. à Bodyweight x .0732 = Result 1.
2) Add the result above to 8.987. à Result 1 + 8.987= Result 2.
3) Divide your wrist circumference by 3.14. à Wrist divided by 3.14 = Result 3.
4) Multiply your waist measurement by 0.157. à Waist x 0.157 = Result 4.
5) Multiply your hip measurement by 0.249. à Hip x 0.249 = Result 5.
6) Multiply your forearm measurement by 0.434. à Forearm x 0.434 = Result 6.
7) Add results 2 & 3. à Result 2 + Result 3 = Result 7.
8) Subtract Result 4 from Result 7. à Result 7  Result 4 = Result 8.
9) Subtract Result 5 from Result 8. à Result 8  Result 5 = Result 9.
10) Add Result 6 and Result 9. The result is your lean body mass (your fat free weight) à Result 6 + Result 9 = Lean Body Mass.
11) Subtract your lean body mass from your bodyweight. Once you get the result, multiply that number by 100. Once you get this result, divide it by your bodyweight. à ((BodyweightLean Body Mass) x 100) divided by your bodyweight.
Example:
A woman that weighs 125, and has a wrist measurement of 6.0, a waist measurement of 24, a hip measurement of 38, and a forearm measurement of 9.5 would calculate her body fat percentage in the following manner. Step 1: 125 x 0.732=91.5. Step 2: 91.5 + 8.987=100.487. Step 3: 6 divided by 3.14=1.91. Step 4: 24 x 0.157=3.768. Step 5: 38 x 0.249=9.462. Step 6: 9.5 x 0.434=4.123. Step 7: 100.487+1.91=102.397. Step 8: 102.3973.768=98.629. Step 9: 98.6299.462=89.167. Step 10: 4.123+89.167=93.29 (Lean Body Weight: Fat Free Weight). Step 11: ((12593.29) x 100) divided by 125 = (31.37 x 100) divided by 125 = 3171 divided by 125= 25.368 (Body Fat Percentage).

Notes: The formulas above are just approximations. The goal here is to have a point of reference from which to work. I recommend that you measure your body fat every three weeks. If you see a pattern where you see yourself gaining muscle and losing fat, then you know your program is right on track. If not, examine which part of your program is not optimal. Assuming that you are following an effective training routine, look at the things that could be going wrong such as you are not getting enough rest at night or more likely you are not following your nutrition plan to the letter.
BV
:bb3:  05232006, 02:18 PM
Just tried this. It offers a pretty good approximation of bodyfat. mine was only 0.9% off from my actual bodyfat %age.
 05232006, 02:23 PM

 05232006, 02:28 PM
These calculations were 0.9% higher than my hydrostatic water tank measurements from a few days ago.
 05232006, 02:39 PM
Where do you have access to a hydrostatic water tank?
 05232006, 03:08 PM
Either my math is off or other systems of measurement are off. Or I hope so cause this puts me back up there in bf% again. Impedence puts me at high 15% to mid 16% depending on normal or atheletic settings and calipers put me at mid 16% but if the 22% i'm getting out of this is correct then I would of had to of been around 30% before which is kinda scary.
196 pounds
37 waist at belly button.  05232006, 03:09 PM
 05232006, 03:10 PM
My university has one. You should ask at yours, they probably have one and it's only like $10 to get it done.
 05232006, 03:11 PM
Originally Posted by Jayhawkk  05232006, 03:15 PM
42 at 238. I wonder why the calipers and inpedence showed different. I think it was 26% before(numbers at the house). Loss is a loss so it doesn't change but it does change the amount of muscle I thought I had and the amount of fat needed to drop to get to where I wanted to get though.
 05232006, 03:33 PM
 05232006, 04:10 PM
Its a good estimate. I found it to be 1% higher than a measurement with my caliper.
 05232006, 04:17 PM
Whelp that settles it. Need to find out how to set the impedence reader to get a closer reading and figure out what the deal with the caliper(probably human error) test is. gonna have both done within the next few days and see the results.
 05232006, 08:25 PM
Definitely worth while calculation method. Thanks JBlaze!
edit:
Sorry BV  just realized thanks to JBlaze that you originally posted this.
ThanksLast edited by Ronin13; 05242006 at 07:38 AM.
 05242006, 01:48 AM
BV, Mwah mwah mwah, i llllloooove you bro, you made my day
the formula says i'm at 14.2%BF at 246, last time i check i was 20% at 233and that was 2 months ago
my waist girth is 36 ,  05242006, 01:51 AM
Originally Posted by Ronin13  05242006, 01:56 AM
Just another props to Vrunga for finding this.
I gotta find a way to get to 265lbs without upping my bodyfat % anymore  05242006, 02:01 AM
It actually is pretty accurate, off about a % point. In put me at 9.5%..Now if I can only get to 200lbs with that BF% and keep a 29" waist..Mwwwahahaha
 05242006, 02:01 AM
Originally Posted by Mess
Hey my friend,
I'm 245 @ 17.5% bf according to the formula. I would love to know how you got to where you are from 233 @ 20%. I'm very interested in hearing any advice you may have for me as I am trying to get to 265lbs without becoming a total fatass .  05242006, 02:01 AM
I'm going to try this tommorow after I wake up and do my morning business. Maybe what I will do is try this method, use my caliper, and use my bodyfat analyzer scale, and determine the average of the 3 figures. I don't really trust anyone of them alone.
Then again maybe I will just fudge the #'s to get the % I want  05242006, 02:36 AM
How do you guys measure your waist girth? Belly out? sucked in? contracted?
 05242006, 02:58 AM
Awesome, thanks BV.
I'm at 15% @ 209lbs. I think I'll be running a cAMP/EctoTropin/Cap + Lipoderm Ultra/Ephedrine/Caffeine log.
 05242006, 03:07 AM
Originally Posted by sir.kevin  05242006, 03:13 PM
Hmmm, it pulls me in a 24%!!!
Really?
Yeh, I think I am off to cry now
On a lighter note, I tried 2 other online bf calculators and one pulled me in at 16%bf and the other at 31% bf!
Talk about random number generator  05242006, 03:35 PM
 05242006, 03:48 PM
Originally Posted by Pitbull954
Similar Forum Threads

What's the most accurate way to measure bodyfat% at home?
By Im Pretty Big in forum SupplementsReplies: 8Last Post: 05222008, 09:57 AM 
How accurate are the bodyfat testers in the gym?
By ChildrenX in forum Weight LossReplies: 3Last Post: 04162007, 03:46 AM 
calorie calculator exericses
By sage in forum Exercise ScienceReplies: 1Last Post: 01182003, 12:19 PM 
BMR calculator for use with YJ's Bulking/Gaining weight sticky
By Matthew D in forum Weight LossReplies: 22Last Post: 01162003, 09:21 AM 
Bodyfat Calculator
By YellowJacket in forum Weight LossReplies: 3Last Post: 01122003, 04:32 PM