Straight hair is measured in its natural state, but our Brazilian virgin hair and curly hair is measured when stretched out. general, straight hair is longer than curly hair, because it lies completely flat when we measured it is ideal to choose one size longer than you would.Straight Virgin hair, true to its length, so buy the size as you wanted. Wavy hair is usually 1.5" shorter (unstraightened), Curly hair is usually 3.0" shorter than Straight hair.