Â 2- to 3-year-old child 9 year-old boy. equivalent of a 9-year-old kid shortest an average 7-year old boy equivalent of a 9-year-old kid http://www.disabled-world.com/artman/publish/heigh... equivalent of a 9-year-old kid 125-130 pounds this this source shortest equivalent of a 9-year-old kid 125-130 pounds equivalent of a 9-year-old kid 3.2kg (~7lb) newborn 125-130 pounds Disabled World equivalent of a 9-year-old kid equivalent of a 9-year-old kid this source @red_seattle: an average 7-year old boy equivalent of a 9-year-old kid