Traditionally , interest for loans and deposits with terms that do not fall neatly into whole years or months is calculated on a daily rate derived from the annual or monthly rate . the balance of the deposit or loan is then multiplied by the daily rate to give the interest . if the daily rate were to contain any recurring decimals , it would have to be rounded up or down to eliminate them , and any discrepancy due to the rounding would be carried over into the multiplication 除了完整年数或月数期限的存款及贷款之外，传统上计算利息的方法是先以年利率或月利率转化为日利率，然后再用所得的日利率乘以有关馀额来计出利息，若果日利率有循环小数则需先四舍五入，而有关偏差也会一并乘入馀额数目。
