3% interest rate is a folk saying of interest rate, which means the monthly interest rate is 0.3%; 3% is relative to RMB, that is, 1 yuan can get 3% interest a month. 3% is 0.3 cents. If you borrow 10000 yuan, the monthly interest at 3% interest rate is: monthly interest = 10000×0.3%× 1 = 30 yuan.

legal ground

Article 26 of the Provisions on Several Issues Concerning the Application of Law in the Trial of Private Lending Cases

If the lender requests the borrower to pay interest at the interest rate agreed in the contract, the people's court shall support it, except that the interest rate agreed by both parties exceeds 4 times the market quotation of one-year loan at the time of the establishment of the contract.

The "one-year loan market quotation" mentioned in the preceding paragraph refers to the one-year loan market quotation issued monthly by the National Interbank Funding Center authorized by the People's Bank of China from August 20th, 20th, 20th19th.