I'm trying them out for that purpose, as well. From searching around what little info I can find on the forums, I am guessing they'd be at a decent processing size between 20 and 28 weeks. I ordered some from Cackle this year & plan to weigh them at 20, 24, and 28 weeks to see how big they are by then. Generally, processed whole chickens weigh about 75% of their live weigh. Next year, we hope to hatch out our own batch of beils and keep better records on their feed consumption for broiler purposes.