Purchased 24mths for 18mth old. Fit perfectly! Like the convenience of disposable swim diapers but they don't hold pee so got this as a second backup. Baby wore disposable and this on top. Incase of blowout. Diaper held up when baby peed on the way to the beach, phew! Also looks great without swim shorts, comfy and baby able to move a around! Prefer over honest brand or similar style. Buttons are a plus!