There are years. But once a month is more common. According to what, it is according to the repayment method.

For example, if the principal and interest are equal, then the interest is paid monthly, and once the monthly interest expires, the principal is also paid monthly; One-time debt service is annual debt service. Specifically, the repayment method is.

If you don't know the repayment method in question, you can't calculate the monthly repayment amount. Even if it is paid off in one lump sum after five years, there are differences in the way of repaying principal and interest once or paying interest once a month. You need to know the specific repayment method to be accurate.