BMI to body fat %
Merkavar
Posts: 3,082 Member
so I just came across this formula which seems to line up with the % from my scale for body fat %.
Just wondering if it's accurate for others.
Anyone mind calculating this and posting the result, along with what you think your body fat % actually is.
Formula is
1.2xbmi + 0.23xage -5.4 for female and -16.2 for males.
See my scales and this formula are 1.4% different.
Just curious as to the accuracy of this formula.
I might post a image of me working out as a reward :P
Just wondering if it's accurate for others.
Anyone mind calculating this and posting the result, along with what you think your body fat % actually is.
Formula is
1.2xbmi + 0.23xage -5.4 for female and -16.2 for males.
See my scales and this formula are 1.4% different.
Just curious as to the accuracy of this formula.
I might post a image of me working out as a reward :P
0
Replies
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The formula gave me 27%. My scale gives me approximately 25%. Actual BF% is unknown.0
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1% is pretty darn close for something that's just a ballpark estimate.0
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I come up with 30% on this, but my scale says 28. I don't know if my scale is entirely accurate, as that puts my LBM on a 5'11 body at 160 pounds.0
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I don't have scales that measure body fat % so, I compared the result of the formula (I got 36.71%) with the body fat % result from the DEXA scan I had in February (25.3%) which is a variance of about 11.4%. Not sure if that helps or not though. It seems I still have a fair way to go.0
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It's within 2% of what I get on various scales and calculators, and I think it's very close from visual estimation.
ARgh ok ok - bmi = 21.1, bf% via your formula = 28.89; I got between 28 and 30 on those scales, last time I checked, a couple of pounds ago. (Yeah I know it's within the average range. Not where I want to be
) 0 -
Formula gives me 27.51%. If I take my DEXA scan lean body mass from about 2 months ago (I've lost some weight since then) and use it with my current body weight, I'm 29.35%.0
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I have four DXA scans and a useless Bio-impedance scale to add to the mix:
BMI 34.5 Body Fat: 38.8% Aria Scale: N/A Your Formula: 36.47%
BMI 31.2 Body Fat: 32.9% Aria Scale: 26.4% Your Formula: 32.51%
BMI 29.4 Body Fat: 29.3% Aria Scale: 24.1% Your Formula: 30.23%
BMI 26.7 Body Fat: 27.3% Aria Scale: 21.9% Your Formula: 27.83%0 -
Gives me 28.02.... I've always felt I was 25% - 20%... I have no way of actually knowing though.0
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Formula is
1.2xbmi + 0.23xage -5.4 for female and -16.2 for males.
That formula says I’m 13.3%. Looking at the formulas at Strength Unbound, the YMCA modified and PN&F formulas both give around 13%. I imagine that that number is fairly close to my real body fat percentage, but I don’t know.0 -
Gave me 22.6, not even close.0
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Gave me 28%. I think I'm <20%. Your formula seems to punish age.0
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Gave me 21.59. Not even close.0
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I calculated my bf% online using a bunch of physical measurements, plus my weight and height. that number (which is too high to mention lol) only differs by a fraction of a percent.0
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So far it seems fairly accurate except for people with avatars of very strong looking people.
I imagine that it’s also inaccurate for somewhat older people who try to stay fit. The formula assumes that your body fat percentage increases with age, but I’m sure that there are some counterexamples to that on this site.
Still, it’s interesting how close it seems to be for someone with an average build.0 -
I got 38.8% my scales this morning gave me 39.3%. Pretty damn close
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so I just came across this formula which seems to line up with the % from my scale for body fat %.
Just wondering if it's accurate for others.
Anyone mind calculating this and posting the result, along with what you think your body fat % actually is.
Formula is
1.2xbmi + 0.23xage -5.4 for female and -16.2 for males.
See my scales and this formula are 1.4% different.
Just curious as to the accuracy of this formula.
I might post a image of me working out as a reward :P
How does that take account of musculature which is a pre-requisite for understanding BF isn't it?0 -
Without meaning to be smug that gives me a BF reading of 34.2
That's out by around 10-11%
I don't think I am a "very strong looking person", although I am old and relatively fit I suppose0 -
so I just came across this formula which seems to line up with the % from my scale for body fat %.
Just wondering if it's accurate for others.
Anyone mind calculating this and posting the result, along with what you think your body fat % actually is.
Formula is
1.2xbmi + 0.23xage -5.4 for female and -16.2 for males.
See my scales and this formula are 1.4% different.
Just curious as to the accuracy of this formula.
I might post a image of me working out as a reward :P
How does that take account of musculature which is a pre-requisite for understanding BF isn't it?
It doesn't, other than some generalized sex-based assumptions built into the equation (the -5.4 for women and the -16.2 for dudes).
Where did you get this formula, @Mercavar?0 -
dondotwinks wrote: »I got 38.8% my scales this morning gave me 39.3%. Pretty damn close
So one bad reading matches another bad reading ?0 -
Should work (on average, like the bmi) for most people in the middle of the bell curve0
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Formula gives me 27%. My scale gave me 15% every morning this week.0
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HazelTrisEverdeen wrote: »This gives me 20.61%. My scale gives me around 17%. I think I should go have my body fat % checked at the doctor's next time just so I actually know.
Dexa scan is your best bet0 -
It gives me 40% which is what my BF % was when I weighet 35kg heavier. My current BF% (measured with a calipur) is 22%.0
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so I just came across this formula which seems to line up with the % from my scale for body fat %.
Just wondering if it's accurate for others.
Anyone mind calculating this and posting the result, along with what you think your body fat % actually is.
Formula is
1.2xbmi + 0.23xage -5.4 for female and -16.2 for males.
See my scales and this formula are 1.4% different.
Just curious as to the accuracy of this formula.
I might post a image of me working out as a reward :P
How does that take account of musculature which is a pre-requisite for understanding BF isn't it?
It doesn't, other than some generalized sex-based assumptions built into the equation (the -5.4 for women and the -16.2 for dudes).
Where did you get this formula, @Mercavar?
A few places, I just googled something like Body fat from BMI. Im not claiming its awesome or for everyone etc. Just it seemed accurate for me and another person so I was curious about others. Its based on the BMI so its going to be inaccurate for some just like the BMI.
http://halls.md/body-fat-percentage-formula/
http://www.livestrong.com/article/173592-how-to-convert-bmi-to-body-fat-percentage/
http://www.caloriecount.com/forums/weight-loss/way-calculate-body-fat-percentage-bmi0 -
These things are typically correlations between measured variables in a sample population. You end up with a cloud of dots and a line passing through the middle. Many dots are a way off the line. Typically the correlation coefficient is <0.7 which implies 30% of the variations are not taken care of by the equation.
They serve a purpose if you only know your height, weight and age but are no substitute for decent measurement.0
This discussion has been closed.
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