hatching % question ( math)

Discussion in 'Incubating & Hatching Eggs' started by okiehen, Feb 27, 2009.

  1. okiehen

    okiehen Chillin' With My Peeps

    Oct 25, 2007
    This is a math question on hatching %.
    I cant get in my head how to get the % hatched.
    Okay lets use this as an example.
    you started with 42 eggs
    5 were clear at 8 days, do you count them ( I don't)
    37 eggs went the full 21 days with chicks developed.
    29 hatched out live chicks
    8 eggs never hatched but had full term chicks in them
    How do you get the % of your hatch?
  2. the_eagle69

    the_eagle69 Chillin' With My Peeps

    Feb 1, 2009
    Far SW VA
    eggs in - eggs out devided by eggs in x100 - 100 = % hatch and i would count the 42 in so you had 42-29=13/42=.31x100=31% - 100% =69% hatch rate Some one let me know if im wrong
    Last edited: Feb 27, 2009
  3. Tuffoldhen

    Tuffoldhen Flock Mistress

    Jan 30, 2007
    Quote:I don't count clears, when I do my percentages of a hatch. Bloodrings or quitters I do but not clears.

    Divide your 37 that you had on day 18 into the 29 live that hatched. 78%
    Last edited: Feb 27, 2009
  4. meriruka

    meriruka Chillin' With My Peeps

    Oct 18, 2007
    If you are not counting the non-fertile eggs, your rate is 29 divided by 37 times 100 equals 78%
  5. speckledhen

    speckledhen Intentional Solitude Premium Member

    If you count ALL eggs, even the clears, you are getting your Fertility Rate, not the hatch rate.

    If you count only the ones that start developing, then you have your hatch rate.

    Make sense? I removed 15 Blue Orp eggs from my last batch, all infertile. Had a butt fluff issue. I do not count those in my hatch rate.

    Started with 42 eggs of several breeds. Of those, 17 were not fertile/clear. So I actually just had 25 eggs that I can get my hatch rate from. 21 hatched, so my hatch rate is 84%. Take 21 divided by 25.
    Last edited: Feb 27, 2009
  6. Clay In Iowa

    Clay In Iowa Chillin' With My Peeps

    Oct 9, 2008
    Near Wilton Iowa
    Quote:That sounds like a personal problem.. [​IMG]

    Is it anything like "junk in your trunk"... [​IMG]

    I kill myself.... [​IMG] [​IMG] [​IMG]
  7. speckledhen

    speckledhen Intentional Solitude Premium Member

    LOL, not quite. Should have said the birds had a butt fluff issue, but since it messed up my plans, it became mine.
  8. okiehen

    okiehen Chillin' With My Peeps

    Oct 25, 2007
    Okay thanks that helps now. My husband was getting 77%
    So every hatch we can take the number of hatched chicks
    divided by the # of eggs that make it to 21 days . this get the right %
    Thanks a bunch.
  9. twigg

    twigg Cooped up

    Mar 2, 2008
    Quote:Never count the clears.

    The total eggs developing at day 7, divided by the number of hatched chicks.

    So .... 29 / 37 = a respectable 78.4%

    The reason clears aren't counted is simple. We are trying to maximise hatch rates, and considering improvements if the rate falls below around 95%.

    The 8 dead-in-shell are an issue you can address.

    If you count eggs that couldn't have hatched, you skew the figures unhelpfully.
  10. Matt A NC

    Matt A NC Overrun With Chickens

    Feb 22, 2007
    Morganton, NC
    x = total number of eggs set
    y = number of eggs that have development at day 10
    z = number of hatched chicks that are viable. Any chicks that have to sadly be culled are not included in this number.

    % Fertility = (y / x) *100%
    % of hatch rate = ( z / y ) *100%


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