Graphing practice on dry erase saves paper. Bold lines separate board into quadrants each 10 squares by 10 squares; total grid is 20 squares by 20 squares. Individual squares measure 1/2" x 1/2" . Plain work space is 11" x 5-1/4" . Boards feature non-ghosting dry erase surface with rounded corners and smooth edges for safety and comfort. Durable hardboard backing is warp and chip resistant.Measure 11" x 16" x 0.125"