The measurements needed to create a scrunchie really depend on whether you want a small or big accessory. For little ones, you will need to cut a piece of fabric to 2.5 x 20 inches (6.5cm x 51cm), and for a bigger one, cut the cloth to 3.5 x 22 inches (9cm x 56cm). The elastic should be 8 inches (20.5 cm) or, if you have long or thick hair, cut it to 9 inches (21 cm) to accommodate for this.