 [ Symptoms ] what are hereditary colon cancer syndromes [ Disease ] at 11 years of age the normal blood pressure range is close to the same as it is for an adult generally speaking the normal blood pressure range for an 11 year old boy or girl is around 11575 to 12585 or thereabouts however this range can vary depending on many factors such as the fitness level of the child a skinny kid who plays a lot of soccer probably will have a lower blood pressure than a larger kid who is not very active in that respect blood pressure in children is not much different from blood pressure in adults if you have concerns about your child is blood pressure you should consult your pediatrician hope this helps