# hatching % question ( math)

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

1. ### okiehenChillin' With My Peeps

Oct 25, 2007
Oklahoma
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?
Thanks

2. ### the_eagle69Chillin' 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. ### TuffoldhenFlock Mistress

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Jan 30, 2007
WV
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. ### merirukaChillin' 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%

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 IowaChillin' With My Peeps

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

Is it anything like "junk in your trunk"...

I kill myself....

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

8. ### okiehenChillin' With My Peeps

Oct 25, 2007
Oklahoma
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. ### twiggCooped up

Mar 2, 2008
Tulsa
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%.

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

10. ### Matt A NCOverrun With Chickens

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53
269
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%

Matt