Broilers are hybrid chickens bred for fast growth and finish. Typically raised to about 5 pounds, they are usually processed between 7 and 9 weeks of age. Birds slaughtered between 9 and 12 weeks of age, typically weigh between 7 and 10 lbs. and are called roasters.
Danko, Tom, "Raising Broilers" (2023). UNH Cooperative Extension. 1494.