How large will my 4 month old kittens be?

I have two male orange tabbies. They just turned 4 months old on July 25 and I'm kinda curious to how large they'll be. Leon weighs around 5.6 lbs as a 11.5 inch long tail and 1 ~ 1.5 inch paws while his brother, Wesker, has a 9 ~ 9.5 inch tail and 1 in paws and weighs about 5.4 lbs. I think they'll be big boys but I'm not sure.

Unfortunately, I don't think there's a way to know without seeing the parents.  It's fun to watch them grow, though!

I think it's still guesswork going by the mother cats' size.  Mine is slightly overweight at a mere 7lb.  My son and his wife have two of her year old tom-kittens, one ginger, one tux, and they are 12lb and 9lb respectively, and not overweight.  At 17 weeks, they were about 6lb each.

I think it's still guesswork going by the mother cats' size.  Mine is slightly overweight at a mere 7lb.  My son and his wife have two of her year old tom-kittens, one ginger, one tux, and they are 12lb and 9lb respectively, and not overweight.  At 17 weeks, they were about 6lb each.

 That is  larger than average for their age;  they're likely to be pretty big boys.   but kittens grow at different rates / different growth spurts.  Just like with kids you can't always predict by a boy's size at age 10 how big he will be as an adult man. 

 If you knew the size of their dad and their mother's brothers ,  that would give you some idea of the likely range of possibility.