I presume you mean cm

^{2}, which means square centimeters, a unit of area. Millimeters (mm) are a unit of length, so you cannot convert one to the other. You can convert cm^{2}to mm^{2}. Since there are 10 mm in 1 cm, there are 100 mm^{2}in 1 cm^{2}. So multiply by 100.