Get Average Weight For 20 Month Old Boy Background. Are you older than 20? By 1 year old, the normal size for boys is 20 to 27.
Based on the birth date and date of measurement, the calculated age is 20 years or older.
Averages for boys birth to 36 months. Children growth chart calculator to determine weight for age percentile. Are you older than 20? Our easy to read optimum height to weight ratio charts, cover newborn babies to teenage girls and boys, and will give you a general idea of whether you are of average weight for your age and height without using complicated percentile.