Bailey's formulas are totally empirical, i.e., he just played around with numbers and formulas until he found a formula that would give a result close to that of underwater body fat testing but without all the hassle. He claims they are accurate to ±2%. But this is for the average male and female. As a person becomes super fit (most dedicated body builders) these formulas will give a result 3-5% higher
than the actual number. For a person who is very skinny but very out of shape they will give a result 3-5% lower
than the actual number. So I think these numbers are good enough for someone just starting to get in shape, but as my body fat gets lower I'll need to do something else.
I don't know about the accuracy of the formula at http://www.mybodycomp.com
. I logged on and typed in my measurements, but the report it generated didn't give me a body fat percent.
It looked like I needed to join ($10/month) to get access to that feature. I'm pretty cheap!
I'd be happy to see the results that other people get with these formulas.
Women 30 years and younger:
hips + (0.8 x thigh) - (2 x calf) - wrist = % body fat
Women over 30 years:
hips + thigh - (2 x calf) - wrist = % body fat
Men 30 years and younger:
waist + (0.5 x hips) - (3 x forearm) - wrist = % body fat
Men over 30:
waist + (0.5 x hips) - (2.7 x forearm) - wrist = % body fat
Where to measure:
measure around the widest part (probably around the belly button), when relaxed... not with stomach pushed out, but not with it sucked in either... and not relaxed like your girlfriend is watching you, either... like you're by yourself and no one else is around. From maximum suck in to totally distended this measurement can vary by 5 inches! and this is where most of the error in the formulas comes from.
don't measure too high. Take this measurement around the widest part of the hips and buttocks with your feet about 4" apart.
For the following measurements, use your dominant side.
measure around the widest part of the upper thigh while standing with your feet about 12" apart.
distribute weight evenly on both feet. Measure at the widest part.
measure at the widest part with your fist clenched so the forearm is flexed.
measure between the bony protrubance and the hand.
Let me know what you think!