%BF by Waist Circumference

jon630 · Post by **jon630** » Fri Mar 20, 2009 2:44 pm

I noticed the following formula on the website:

LBW= 44.636 + 1.0817(wt) &SHY; 0.7396(c)

wt = Body weight (Kg)
c = Circumferences of Umbilicus Abdomen (cm)

I am not getting correct answers when I plug in numbers. Is there a part of the formula I am missing? What is the relationship between the two parts of the formula?

Thanks.
Jonathan

Post by **Ironman** » Fri Mar 20, 2009 5:12 pm

You subtract the result of the second from the result of the first.

So the formula is this.
(44.636 + 1.0817W) - (0.7396C)=L

So you follow the order of operations. You first multiply 1.0817 by your weights in kilos. Then you add 44.636 to it. You then move over to the other set of () and you multiply your weight in centimeters by 0.7396. You should not have a number in each (). You subtract the second number form the first one. That is an rough ballpark estimate of your lean body mass.

igquick · Post by **igquick** » Mon Jun 28, 2010 3:43 am

This body weight to waist ratio doesn't prove your fat percentage. I use accu measure calipers which you can buy online for chump change. My waist size is 35 and I weight 165 but my body percentage is 7%. I also verified this with a personal trainer.

Post by **stuward** » Mon Jun 28, 2010 6:48 am

As Ironman said, it's a rough measure. You should also keep in mind that calipers will underestimate body fat on a person with high visceral fat. I'm not saying that's your case, I expect you have a larger waist due to genetic reasons. There are a lot of variations between people that quick and easy estimating methods will, by necessity, ignore.

igquick · Post by **igquick** » Mon Jun 28, 2010 3:16 pm

True, but isn't calipers more effective then body to waist fat percentage ratios?

frogbyte · Post by **frogbyte** » Mon Jun 28, 2010 4:03 pm

Probably depends on who's eye-balling the caliper.

Post by **stuward** » Mon Jun 28, 2010 4:20 pm

igquick wrote:True, but isn't calipers more effective then body to waist fat percentage ratios?

I never said waist measurement was better, just that neither is perfect. Frogbyte is right, it depends on the user. Either way, it's a guideline and it's the changes that matter.

igquick · Post by **igquick** » Mon Jun 28, 2010 4:43 pm

I never claimed that you said that waist measurement was better, I was just asking.

ApolytonGP · Post by **ApolytonGP** » Mon Jun 28, 2010 11:04 pm

In general, calipers are a good method.

I have had them done on me a lot when I did competetive sports requiring weighins. Good trainers will be very repeatable and correlate well to each other. you have to know how to measure for the right spot and get a good pinch. 6 spot Yahazs (sp?) method is what I have done at the YMCA by the phys therapist wannabe. It's great. I don't even pay anything. Just chat him up. gonna help him with some chemistry tutoring if he needs it.

Leigh Peele has a good video on bf methods and fat patterning in men/women. Very illuminating.

igquick · Post by **igquick** » Tue Jun 29, 2010 12:58 am

I use accu measure and sometimes a trainer with calipers for free but I have to pretend Im taking a PE class. Thats cool that you get it for free, because trainers that get your fat percentage costs money.

Post by **Ironman** » Tue Jun 29, 2010 4:06 am

One caveat with calipers. If you have loose skin, it will measure you low.

igquick · Post by **igquick** » Tue Jun 29, 2010 10:34 am

I don't have loose skin, unless I was fat when I was younger, then suddenly lost a significant amount of body weight.

ApolytonGP · Post by **ApolytonGP** » Tue Jun 29, 2010 1:31 pm

Ironman wrote:One caveat with calipers. If you have loose skin, it will measure you low.

Great insight. Relevant to me. I lost a lot of fat, very rapidly and have some of this. Hmm. Maybe I should get a Dexa.

This would imply that I could take my weight significantly lower. I'm at 165 and 10%. I've been suspecting this is shaded low, despite the (I think) skill of calipers (based on pervious eperience when younger and this fellow being pretty exacting). I didn't want to go much under 10% given my age and a desire to build muscle. But maybe I could safely go down to 160 or even 155 and still keep needed fat levels for hormones and all that.

Hmmm. Dexa is only 200 bucks.

Post by **Ironman** » Wed Jun 30, 2010 2:15 am

ApolytonGP wrote:
Ironman wrote:One caveat with calipers. If you have loose skin, it will measure you low.
Great insight. Relevant to me. I lost a lot of fat, very rapidly and have some of this. Hmm. Maybe I should get a Dexa.

This would imply that I could take my weight significantly lower. I'm at 165 and 10%. I've been suspecting this is shaded low, despite the (I think) skill of calipers (based on pervious eperience when younger and this fellow being pretty exacting). I didn't want to go much under 10% given my age and a desire to build muscle. But maybe I could safely go down to 160 or even 155 and still keep needed fat levels for hormones and all that.

Hmmm. Dexa is only 200 bucks.

In the picture I saw you looked like you had similar bodyfat % and amount of loose skin as I do. I was fatter than you, but I've gained more muscle too. That helps take up some of that skin. Calipers show me at about 10%, but I'm probably more like 15.

If you get an impedance machine with an "athlete" mode on it, it may be accurate for you. I've gotten far too big for it, so mine measures me high.

ApolytonGP · Post by **ApolytonGP** » Wed Jun 30, 2010 12:08 pm

Impedance is crap. I'm going to get dexaed.