Want to know for certain how much should a child weigh?

Growth charts: Since you did not give an age, gender or height for the child, it is difficult to give an answer. If you will go to the cdc website you can print off a growth chart which will give the height & weights for kids at different ages. The expected weight should correspond to the child's age & height on the chart. See: www.Cdc.Gov/growthcharts/cdc_charts.Htm.