At what age do kids start high school in the US?

While there is no set standard for American high schools, some generalizations can be made about the majority. Local, elected school districts manage public schools. There is a range in quality from basic education to more intellectually-stimulating environments for students approximately 14 to 18 years of age. Students enter around the age of 14 (sometimes 13) and pass through four years (sometimes five).

Source: Wikipedia