Abstract: Procedure for the calculation of interests for entrustments of money comprising: memorization of quantities of money K indicative of the possible amounts of credit granted; memorization of an additional remuneration M indicative of the requirements of the lender for granting the loan; processing of an additional amount of money L indicative of the risk of loss borne by the lender; and mathematical combination, according to a given formula, of the aforementioned quantity of money K, extra yield M and amount of money L, in order to obtain a quantity of money B that, asked of the borrower, allows the lender to obtain an average return of (K+M).