Legal Analysis: Calculation standard of overdue payment interest: It can be calculated based on the benchmark interest rate of similar RMB loans of China People's Bank in the same period with reference to the standard of overdue penalty interest rate.

Legal basis: Article 676 of the Civil Code of People's Republic of China (PRC). If the borrower fails to repay the loan within the agreed time limit, it shall pay overdue interest in accordance with the agreement or relevant state regulations.