Jazz pants have an elastic waistband for easy changing and comfort. Fabric is a mix of cotton, spandex that result in a quality fabric. Child 4-6: Waist: 17.72"/45cm; Length: 25.59"/65cm Child 6-7: Waist: 19.29"/49cm; Length: 28.94"/73.5cm Child 8-10: Waist: 21.26"/54cm; Length: 33.86"/86cm Child 12-14: Waist: 22.05"/56cm; Length: 34.65"/88cm