How To Size A Dirt Bike For Your Kid Child AgeChild HeightEngine Size In CC 3 – 7-years2ft 7-inches To 3ft 7-inches50cc 7 – 12-years3ft 7-inches To 4ft 7-inches50cc – 110cc 12 – 14-years5ft To 5ft 2-inches125cc 14 – 16-years5ft 2-inches To 5ft 8-inches125cc – 250cc May 11, 2021