Hawaii Revised Statutes Division 2. Business § 412:9-306

(1) The amount of the refund on a loan with an original term of sixty months or less shall be computed under a method no less favorable to the borrower than the Rule of 78ths method (also known as the Sum of the Digits method). The refund shall represent at least as great a proportion of the total finance charge as the sum of the periodical time balances, after the day of prepayment, bears to the sum of all the periodical time balances under the schedule of payments in the loan agreement;

(2) If the original term of a precomputed loan exceeds sixty months, the amount of refund of unearned interest shall be equal to the difference between the total interest originally charged and the actuarially earned amount;

(3) Refunds on precomputed loans originated prior to July 1, 1993, shall be made in accordance with the terms of existing loan agreements, provided that the refund provision complied with applicable law at the consumer loan origination.