Your mortgage payment is constant through time but the fraction of it that goes to paying off principal versus interest changes through time and it just changes as dictated by this formula.

抵押贷款每月还款是固定的,但是其中本金和利息的比例关系,会随时间而改变,这是由这个公式所决定的

耶鲁公开课 - 金融市场课程节选

If you do it in monthly terms your interest rate is r/12 because there are twelve months in a year.

如果是每月还款那么月利率是r/12,因为一年有12个月

耶鲁公开课 - 金融市场课程节选

If they quote the rate on the mortgage, call that r Traditionally you would be paying monthly.

如果给定贷款利率,记为r,通常你是每月还款

耶鲁公开课 - 金融市场课程节选