How much should my 5-month-old weigh?

I am trying to figure out how much my 5 month old should weigh...he was born a couple weeks early and developed a touch of rsv...then he got bronchilitis and the doctors have told me to put him on cereal in his bottles so im just trying to get an idea of what his ideal weight is...all help is greatly appreciated...thanks

When my daughter was 5 months she weighed about 15 pounds. Put him on cereal it will make him gain weight.

it depends on how much he weighed when he was born