Body Fat %

karagetsfit
karagetsfit Posts: 191
in Fitness and Exercise
I don't have a proper way to measure my body fat % to know it 100%. I know all tools outside of the bodpod and the water method are estimations. I'm okay with that.

I have done the tape measure way and a trainer at the gym uses calipers.

I am curious as to how much weight I would have to lose to get to my goal body fat %? Again, I know it's an estimation. I've seen some formulas but I am terrible with math. I haven't found any calculators for it or maybe I haven't looked hard enough.

If anyone would be able to help me out, that'd be great!

Currently 159.6lbs, 5'9, 20.8%
My goal weight is 140 and goal BF% is 15%

Replies

  • karagetsfit
    karagetsfit Posts: 191
    BUMP
  • ksavy
    ksavy Posts: 271 Member
    http://www.fat2fitradio.com/tools/ibw/

    Put in weight and body fat :)
  • porffor
    porffor Posts: 1,210 Member
    Can I ask how the calipers compared to the measurements?

    I am using a handheld 'thing' but am a bit nervous to ask my gym (just joined) for a BF caliper reading.. i know it'll be high but want to work on it.
  • michellekicks
    michellekicks Posts: 3,624 Member
    If your current weight is 159.6 lbs and your BF % is 20.8%, then 20.8% of your current weight is fat weight and the rest is lean...

    So 20.8x159.6/100 = 33.2 lbs fat... and the rest is lean: 159.6 - 33.2 = 126.4 lbs.

    If you want to be 15% BF (which is really low btw...) you can either aim to lose more fat or gain more muscle. Assuming, however, you just want to lose fat, you'd want to maintain your 126.4/(100-.15) = 126.4/.85 = 148.7 lbs.

    And to check the math: 148.7-126.4 = 22.3 and 22.3/148.7 = 15%

    So your goal weight is 148.7 lbs.

    Did I get it? Do I win a prize?
  • Azdak
    Azdak Posts: 8,281 Member
    Based on your numbers, I am not sure your BF% is accurate. At 20.8%, that would give you a Fat Free Mass of 126 lbs. Even at your height, that's a little on the high side, unless you have been pushing some heavy weights for awhile.

    20.8% for a woman, while not super athletic, is still pretty lean.

    I would shoot for 140-145 and then reevaluate how your look and where to go from there. That would likely put you in the neighborhood of a real 20% BF and I suspect you would be satisfied.
  • michellekicks
    michellekicks Posts: 3,624 Member
    Based on your numbers, I am not sure your BF% is accurate. At 20.8%, that would give you a Fat Free Mass of 126 lbs. Even at your height, that's a little on the high side, unless you have been pushing some heavy weights for awhile.

    I'm 5'7" and my fat-free mass is 120 lbs as measured by DEXA and I haven't lifted weights in almost 20 years. Just thought I'd throw that out there... you can't really guess at someone's body composition.
  • Azdak
    Azdak Posts: 8,281 Member
    Based on your numbers, I am not sure your BF% is accurate. At 20.8%, that would give you a Fat Free Mass of 126 lbs. Even at your height, that's a little on the high side, unless you have been pushing some heavy weights for awhile.

    I'm 5'7" and my fat-free mass is 120 lbs as measured by DEXA and I haven't lifted weights in almost 20 years. Just thought I'd throw that out there... you can't really guess at someone's body composition.

    Any "guess" is fraught with peril, I will admit, and I can appreciate your skepticism.

    However, having done over 10,000 body composition tests, I can actually tell quite a bit from looking at a profile pic and getting some basic information about a person and when I feel confident about my conclusions, I am comfortable sharing them if I think they can provide some insight.
  • karagetsfit
    karagetsfit Posts: 191
    Can I ask how the calipers compared to the measurements?

    I am using a handheld 'thing' but am a bit nervous to ask my gym (just joined) for a BF caliper reading.. i know it'll be high but want to work on it.

    It varies about 2-3% which is okay since the tape measure is just an estimation as well. I haven't gotten my measurements done at the gym yet this month, probably on Monday.
  • karagetsfit
    karagetsfit Posts: 191
    If your current weight is 159.6 lbs and your BF % is 20.8%, then 20.8% of your current weight is fat weight and the rest is lean...

    So 20.8x159.6/100 = 33.2 lbs fat... and the rest is lean: 159.6 - 33.2 = 126.4 lbs.

    If you want to be 15% BF (which is really low btw...) you can either aim to lose more fat or gain more muscle. Assuming, however, you just want to lose fat, you'd want to maintain your 126.4/(100-.15) = 126.4/.85 = 148.7 lbs.

    And to check the math: 148.7-126.4 = 22.3 and 22.3/148.7 = 15%

    So your goal weight is 148.7 lbs.

    Did I get it? Do I win a prize?

    I don't get how it's really low, especially if I want to do competitions in the future.

    But you did answer my question and totally confused me at the same time (hate math) so thank you!!! I will re evaluate my goals when I get to that weight!
  • karagetsfit
    karagetsfit Posts: 191
    Based on your numbers, I am not sure your BF% is accurate. At 20.8%, that would give you a Fat Free Mass of 126 lbs. Even at your height, that's a little on the high side, unless you have been pushing some heavy weights for awhile.

    20.8% for a woman, while not super athletic, is still pretty lean.

    I would shoot for 140-145 and then reevaluate how your look and where to go from there. That would likely put you in the neighborhood of a real 20% BF and I suspect you would be satisfied.

    It's an estimation based on the tape measure method. I don't have access to getting a real body fat % reading.
  • karagetsfit
    karagetsfit Posts: 191
    Bump
  • susannamarie
    susannamarie Posts: 2,148 Member
    http://www.fat2fitradio.com/tools/ibw/

    Put in weight and body fat :)

    Do this. It'll do the math for you.
  • porffor
    porffor Posts: 1,210 Member
    Can I ask how the calipers compared to the measurements?

    I am using a handheld 'thing' but am a bit nervous to ask my gym (just joined) for a BF caliper reading.. i know it'll be high but want to work on it.

    It varies about 2-3% which is okay since the tape measure is just an estimation as well. I haven't gotten my measurements done at the gym yet this month, probably on Monday.

    Which method do you use for the measurement test? There are two on the 'fat2fitradio.com tools and the military one has me slightly over my handheld machine, but the other one (taking more measurements) has me lower by nearly 20%.. I can't see - that I'm as low as that one. Much as I'd love to be. lol

    Good luck with your competing :)
  • karagetsfit
    karagetsfit Posts: 191
    http://www.fat2fitradio.com/tools/ibw/

    Put in weight and body fat :)

    Do this. It'll do the math for you.

    AWESOME! Thanks so much!
  • Imanido
    Imanido Posts: 186 Member
    http://www.fat2fitradio.com/tools/ibw/

    Put in weight and body fat :)

    Do this. It'll do the math for you.

    This is shocking! There are 3 methods and using the same measures they all give VERY different results! I find it really frustrating for someone that really would like to know their body fat % (that is "me") :-(
  • karagetsfit
    karagetsfit Posts: 191
    http://www.fat2fitradio.com/tools/ibw/

    Put in weight and body fat :)

    Do this. It'll do the math for you.

    This is shocking! There are 3 methods and using the same measures they all give VERY different results! I find it really frustrating for someone that really would like to know their body fat % (that is "me") :-(

    No calculator is going to give you a completely accurate measurement. I did all 3 of the calculators and figured out my 'goal weight' with each one. I figure I will just reach my original goal weight and see where I am at then.
    If you want to get a real accurate reading, you need to find somewhere local that has a bodpod.
  • invictus8
    invictus8 Posts: 258 Member
    I use Accumeasure:
    http://www.accumeasurefitness.com/

    You pinch above the belly button and to the right a bit. The caliper is reasonably accurate. Much better than tracking one's weight.
  • McBully4
    McBully4 Posts: 1,270 Member
    she is 140 with 15% BF

    4141271.JPG
  • karagetsfit
    karagetsfit Posts: 191
    she is 140 with 15% BF

    4141271.JPG

    That's the look I have in my head, minus the fake tan and boobs. Thanks!
  • karagetsfit
    karagetsfit Posts: 191
    I use Accumeasure:
    http://www.accumeasurefitness.com/

    You pinch above the belly button and to the right a bit. The caliper is reasonably accurate. Much better than tracking one's weight.

    These are the calipers I have. But I don't think their accurate for me. Well, I did it again and it says 24.5 so that is probably accurate. More accurate than the tape measure.
  • shanae727
    shanae727 Posts: 546 Member
    You would actually need to lose about 18-19 lbs putting you at 141lbs ( I did round some numbers).

    My equation (ACE):

    100-24.5=75 (rounded)
    .75 x159.6 (CW)=119.7 ( I used 120) So your lean mass is 120 lbs
    120/.85 (100-15 *your desired bf%)=141lbs (DW-desired weight)

    So you would subtract CW and DW. But anyway I hope that helps! :)

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