The average healthy weight of a 2 year old boy is 27.5 lbs but some 2 year old boys may weight a little more or a little less.
Usually as long as the 2 year old boy is weighing at least 27 lbs in weight then they are usually healthy.
One of my boys weighed 27 lbs at 2 years old and the other weighed 28 lbs so it can vary as every child is built different.
But as long as your 2 year old is not under 27 lbs in weight then they likely are healthy but if you're worried take them to the doctor to be sure they are not underweight.
A 2 year old girl should usually weigh around 26 lbs to 26.5 lbs.