According to Baby Center, the average weight for a 6-year-old boy is between 41.9 and 50.6 pounds. The average height for a 6-year-old boy is 44.2 to 46.9 pounds.
Children grow at different rates, and if your child is below average in height or weight, then he could catch up to their age group as he grows older. According to Baby Center, the data collected for average height and weight is determined by children who fall between the 25th and 75th percentile of height and weight in their age group. Your child could be in the lower or upper 25th percentile and still be healthy.