OK I know a3 a4 a5 b4 b5 and so on is paper size but what I cant find is it 8x10 11x14 and so on help

A4 paper = 210 x 297 millimeters (8.27 x 11.69 inches) A3 paper = 297 x 420 millimeters (11.69 x 16.54 inches) Wikipedia gives the full list - Paper Sizes