Body Fat vs. BMI

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femmerides
femmerides Posts: 843 Member
in Fitness and Exercise
Okay so I am WAY confused. So my BMI is 31.78...however, according to http://www.bmi-calculator.net/body-fat-calculator/, my body fat is 27.55% body fat. which puts me in the "acceptable" range. It does make a little bit of sense because I've always had a lot of muscle and I've always been relatively fit and I used to lift HEAVY weights for my legs (think over 500lbs).

Anyways, if I weigh 191lbs and I'm at 27.55% body fat, that means my lean body mass is 138.38lbs...so if i want to be at 18% body fat, that means I'll weigh 172.76lbs....I'm 5'5"...lol. My goal has been 139lbs just because that's what the BMI chart said was in my range...

So am I doing this all completely wrong? Do any of you out there know how to properly calculate this? If any of you are going to go to the site and want to figure it out for me, here are my measurements:

weight: 191lbs
waist: 36.5"
wrist: 6.5"
hips: 45"
forearm: 10.25"

with these measurements I got this info:

Body Fat: 27.55% (Acceptable)
BMI: 31.78
BMR: 1673.85
Waist to Hip Ratio: 0.81

So according to the site, if I really do aim for my original goal of 139, then I will only have 1% body fat. lol.

Help me understand this a bit better...someone...please. :-) Thanks in advance!
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Replies

  • trigrrl
    trigrrl Posts: 104 Member
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    this is the exact issue with BMI...people who are heavy with muscles ( ex body builders ) often get shown as obese
    i would look at body fat and measurements...i was just reading that some fitness gurus are now looking at the basic height / hips ratio since it would be a better system

    my 2 cents
  • melizerd
    melizerd Posts: 870 Member
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    I think that where you are is likely fine. BMI is only PART of the story of a healthy weight so you've looked at the other pieces too and that matters.

    BMI is not the end all be all, just ONE of the many tools.
  • br0seidon
    br0seidon Posts: 19
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    Measurements are much more accurate than any BMI calculator.
  • bella8282
    bella8282 Posts: 188 Member
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    BMI is not an Exact accurate Science, although I do believe it has it's place. Just not everyone fits the mold.
    BMI takes in no consideration to Muscle Mass, Build/Frame.
    Thats why 2 people of the same height and weight can look very very different, one can appear to look pounds heavier than the other and wear bigger sized clothing. One can be very more muscular the other carrying alot more "fat" ... one could have a slight frame... the other Broad - the scenario's could just keep going, But their BMI would indicate the same "healthy" level
    BMI can be a great tool in finding your "weight" range- but everyone is individual and it cant be soley relied apon in alot of cases- It's best to have a Dr. or Dietician help you work out the best Weight for you with using BMI as a GUIDE only.
    Good Luck.
  • MelL1205
    MelL1205 Posts: 1,200 Member
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    this body fat calculator estimates significantly lower than any test that has ever been performed on me... there is a LARGE discrepancy between what they say my body fat is versus what it really is. Try another!
  • Swimgoddess
    Swimgoddess Posts: 711 Member
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    Knowing my body fat % definitely helped me readjust my goal weight. If you look at my stats in my signature, of the first 6lbs I lost scale-wise, I actually lost 11lbs fat and gained 5lbs lean weight. My original goal was 138, now I've revised it to 142-145ish. I prefer the fat to come off first of course, but I only have 10lbs non-essential body-fat at the moment. If I prioritized the number on the scale, some of that lean weight would probably have to go. The scale number is no longer my biggest priority anymore. It'll come off when it comes off. I only lost 1lb last month and there's an appreciable difference in my overall tone if you see my pics in the "swimsuit competition" thread. Figure the composition you would want for your ideal weight, how many lbs lean & how many fat for if you were say, 22-24%? Then work towards that. Periodically recheck your BF% (about 1x a month) for your updated weight and figure out the changes in lbs of fat lost and lbs lean weight lost OR gained. You may not necessarily NEED that much lean weight to move your body around once you are a bit lighter. It's ok to lose more weight to get within a more ideal BMI so long as your periodic BF% checks show that you are the same composition or even if your BF% drops a little.
  • lauristewart
    lauristewart Posts: 379 Member
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    My BMI says I am over weight and I wore a size 6 dress today......ummmmmm........something might be wrong with that picture!!!! LOL!!! I agree with everyone else....I do workout 3x a week with weights and you lose inches with weights, but not so much weight on the scale sometimes.......anyhoo, thought I would put in my 2 cents!! Just keep doing what you are doing!! You are doing awesome!!
  • crisanderson27
    crisanderson27 Posts: 5,343 Member
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    My BMI says I am over weight and I wore a size 6 dress today......ummmmmm........something might be wrong with that picture!!!! LOL!!! I agree with everyone else....I do workout 3x a week with weights and you lose inches with weights, but not so much weight on the scale sometimes.......anyhoo, thought I would put in my 2 cents!! Just keep doing what you are doing!! You are doing awesome!!

    It's ok, I'm NOT a bodybuilder, and NOT an 'ex bodybuilder'...and the BMI chart says I'm borderline obese lol. That's at my current weight of 181lbs (very near the picture below)...at approximately 19% body fat.

    No thanks...that thing's out the window for me.
  • femmerides
    femmerides Posts: 843 Member
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    thanks everyone. i ended up going and trying about 10 other body fat estimators and the range is between 32% and 42% body fat. lol. so i think the only way i can really know is by getting a caliper thingy and doing it that way. thanks for all your input!
  • femmerides
    femmerides Posts: 843 Member
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    BMI is not an Exact accurate Science, although I do believe it has it's place. Just not everyone fits the mold.
    BMI takes in no consideration to Muscle Mass, Build/Frame.
    Thats why 2 people of the same height and weight can look very very different, one can appear to look pounds heavier than the other and wear bigger sized clothing. One can be very more muscular the other carrying alot more "fat" ... one could have a slight frame... the other Broad - the scenario's could just keep going, But their BMI would indicate the same "healthy" level
    BMI can be a great tool in finding your "weight" range- but everyone is individual and it cant be soley relied apon in alot of cases- It's best to have a Dr. or Dietician help you work out the best Weight for you with using BMI as a GUIDE only.
    Good Luck.

    ya i agree. my two older sisters are the same size as me (14's) but one weighs 210 and is 5'3", the other weighs 185 and is 5'5" and i weigh 191 and am 5'5". I tried on my 12's today and they fit perfectly so now i'm technically smaller than my sisters but the differences between our bodies is amazing. lol
  • femmerides
    femmerides Posts: 843 Member
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    this body fat calculator estimates significantly lower than any test that has ever been performed on me... there is a LARGE discrepancy between what they say my body fat is versus what it really is. Try another!

    ya, i tried out a bunch more and i think i'm probably closer to the 32%+ range. :( oh well. at least i'm 14.5" smaller and 8.8lbs lighter (than i was 4 weeks ago). :D
  • ninerbuff
    ninerbuff Posts: 48,699 Member
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    BMI says I'm overweight. It's outdated. Better to use BF% to gauge yourself. Men should be 15%-20% and females 20%-25% for normal readings.
  • LilRedRooster
    LilRedRooster Posts: 1,421 Member
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    When I was down to 18-19% body fat, my BMI was bordering overweight. I don't bother with BMI anymore, because it's never been remotely accurate for me.
  • mamaDaisyJ
    mamaDaisyJ Posts: 395
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    thanks everyone. i ended up going and trying about 10 other body fat estimators and the range is between 32% and 42% body fat. lol. so i think the only way i can really know is by getting a caliper thingy and doing it that way. thanks for all your input!

    I got one of them fancy scales that measure body fat percentage through electrical impedence. It is consistent, and I read its a good alternative to water weighing and calipers.
  • crisanderson27
    crisanderson27 Posts: 5,343 Member
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    thanks everyone. i ended up going and trying about 10 other body fat estimators and the range is between 32% and 42% body fat. lol. so i think the only way i can really know is by getting a caliper thingy and doing it that way. thanks for all your input!

    I got one of them fancy scales that measure body fat percentage through electrical impedence. It is consistent, and I read its a good alternative to water weighing and calipers.

    I have one too...and while it is consistent, it consistently reads as little as 7%, and as much as 11% higher than calipers...=D. I hate to tell you this hun, but for the most part those things are a gimmick.
  • cheddarboy
    cheddarboy Posts: 124 Member
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    Yep, unfortunately BMI doesn't work well for most men. It was originally developed as a quick method of generalizing health of populations for statistical databases. I'm in the same boat, I'm around 16%BF, yet overweight / borderline obese, lol
  • xraychick77
    xraychick77 Posts: 1,775 Member
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    you cant estimate body fat by online calculators..the only reliable way is a dexa scan.

    even those bio electrical devices are not very reliable.
  • Swimgoddess
    Swimgoddess Posts: 711 Member
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    thanks everyone. i ended up going and trying about 10 other body fat estimators and the range is between 32% and 42% body fat. lol. so i think the only way i can really know is by getting a caliper thingy and doing it that way. thanks for all your input!

    I got one of them fancy scales that measure body fat percentage through electrical impedence. It is consistent, and I read its a good alternative to water weighing and calipers.

    I have one too...and while it is consistent, it consistently reads as little as 7%, and as much as 11% higher than calipers...=D. I hate to tell you this hun, but for the most part those things are a gimmick.

    Yeah, calipers gives me 19.8%, the measuring tape test found here http://www.healthcentral.com/cholesterol/home-body-fat-test-2774-143.html#accurate gives me 22% and my Tanita BI electronic scale gives me a whopping 34%!
  • femmerides
    femmerides Posts: 843 Member
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    i need to get me some calipers!
  • crisanderson27
    crisanderson27 Posts: 5,343 Member
    Options
    thanks everyone. i ended up going and trying about 10 other body fat estimators and the range is between 32% and 42% body fat. lol. so i think the only way i can really know is by getting a caliper thingy and doing it that way. thanks for all your input!

    I got one of them fancy scales that measure body fat percentage through electrical impedence. It is consistent, and I read its a good alternative to water weighing and calipers.

    I have one too...and while it is consistent, it consistently reads as little as 7%, and as much as 11% higher than calipers...=D. I hate to tell you this hun, but for the most part those things are a gimmick.

    Yeah, calipers gives me 19.8%, the measuring tape test found here http://www.healthcentral.com/cholesterol/home-body-fat-test-2774-143.html#accurate gives me 22% and my Tanita BI electronic scale gives me a whopping 34%!

    That's about how they all three work for me too lol.

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