This self-healing cutting mat features grids and markings in both inches and centimeters -- one on each side. Omnigrid Double Sided Mat Inches/Centimeters, 12in x 18in/30cm x 45cm: - Features: This self-healing cutting mat features grids and markings in both" and centimeters-- one on each side The inches side has a 12in x 18in grid spaced every 1in with 1/8in increments on the edge rulers The centimeter side has a 30in x 45cm grid spaced every 1cm with 1/2cm increments on the edge rulers Both sides also have 45-degree angles lines included