I'm running a spreadsheet for mine.
I got my chicks June 2. Everything for them had to be built or bought from scratch and I was able to scavenge very little.
My first hen started laying Nov 1; since then 3 others have started, but two are very inconsistent. I have a total of 6.
I track total costs and feed-only costs. My total costs are currently $14.89 per egg; my feed-only cost is $1.59 per egg.
If my hens average 4 eggs per week per hen, I'll break even in feed costs (assuming "even" is $3.00/doz organic eggs) in about 8 months (that's a bit fudged, since they're not all laying yet, so it's going to be a while before I start to hit that average, so let's say 12 months).
Breaking even overall will take much longer. I'll be converging in about 5 years. Both of these numbers are figured projecting costs, though I didn't try to figure in inflation, so they'll be off a bit... but then, my ladies aren't in contract anyway, so the egg numbers are off a bit anyway
Of course, neither of these take into account bug patrol or fertilizing done by the hens, or the fact that I've been using them to take the sod off.