Abstract: A selectively installable calf support having a seat portion for overlay on the lower seating surface of a child safety seat and a moveably connected extension portion extending forwardly therefrom that is retained in a forwardly and downwardly angled position by contact between the extension portion and the forward portion of the seating portion of the safety seat to support an occupant's legs. The extension portion may include stiffening elements to limit the amount of deflection thereof during use and a folding joint enabling the extension portion to be folded to position above and adjacent to the seat portion for storage when the seat is not occupied. Provisions to selectively secure the calf support to the safety seat may also be provided.