According to the annual interest rate of the benchmark loan of 6.55% and the repayment method of matching principal and interest, the monthly payment is 250,000 years (300 months) 1.695.84 yuan.

If you want to calculate manually, you have to divide 6.55% by 12 months to get the monthly interest rate of 0.5046, and then calculate (1+0.5046%) 300, which is the so-called monthly compound interest coefficient. The calculation of this compound interest coefficient also needs the help of a calculator.

As for the latter formula, it is a quick calculation formula. If you count the compound interest coefficient, loan amount and loan term, the amount of calculation is still very large.