1 pound per square inch:
we know that 1 kg is 2.2 pounds, and 1 inch is 2.54 cm
1 square inch = 2.54 x 2.54 cm^2
1 pound = 1/2.2 kg
so if you take (1/2.2)/(2.54 x 2.54), you will get the multiplier for psi-to-kg/cm^2. Windows calculator shows around 0.0704, i.e. 1psi is around 0.07 kg/cm^2