To calculate the social security contribution base, you have to divide the previous year’s total income by 12.
For new hires, the starting salary may be used as the social security base during the first year.
It’s important to remember that the base figures for social security contributions are capped at a certain amount. Generally, the contribution base is capped at 300 percent of the average local salary. And the minimum contribution base is usually decided either by the local minimum wage or a certain percentage of the average local wage.
In Shanghai, starting from July 2021, the maximum social insurance contribution base was raised to RMB 31,014, and the minimum contribution base was raised to RMB 5,975.