A4 Paper vs A5 Paper

The A4 Paper and A5 Paper are most easily told apart by their overall size. On height, the A4 Paper measures 297.0 mm against the A5 Paper's 210.0 mm — about 87.0 mm more. On width, the A4 Paper measures 210.0 mm against the A5 Paper's 148.0 mm — about 62.0 mm more. They match almost exactly in thickness, at 0.1 mm.