Im asking because I dont really want to give them away until they have been fixed so that I don't have to worry about others allowing them to breed.
Well this is an old thread.
Do call your vet and see what they say, it does go by weight rather than age and some are still stuck on the old 6 months. Really, the sooner the better. Girls are best done before their first heat cycle which can happen at 4 months.
I do my kittens at 10 weeks, and microchip at the same time (with vaccines at 8 & 12, so the neutering fits in the middle of this schedule)