OAR 441-730-0160: Daily-Interest Computation

(1) When interest on a loan is computed on a daily basis using a 360-day factor, the maximum charge for each day must be 1/30 of the monthly rate. In determining the elapsed time to compute interest on any such loan, each calendar month shall be treated as containing 30 days. However, when the period for which interest is computed includes the last day of the month: (a) If the month has 31 days, the 31st day must be ignored: (b) If the month is February, two days must be added to the period, except in leap year when only one day may be added. (2) Interest on a loan may be computed on a daily basis using a 365-day factor or, in a leap year, a 366-day factor. In determining the elapsed time to compute interest or a refund of interest, on such a loan, the maximum charge for each day must be 1/365th of the annual rate, except in a leap year when the maximum charge for each day must be 1/366th of the annual rate.