The compound interval, or frequency, is the interval at which interest is compounded when calculating amortizing loan payments.

In the United States, most loans are compounded monthly. This means that the interest rate is applied to the original principal of the loan as well as to all accumulated interest on a monthly basis.

Other countries have different compound intervals. For example, in Canada, loans are typically compounded semi-annually. This means that the interest rate is applied to the original principal of the loan as well as to all accumulated interest every 6 months.