Based on 365 days per year, [365/7 (days per week) = 52.14 weeks per year] so 52 weeks per year, based on a bi-weekly period = 52/2 = 26 payments per year/12 (Months) = 2.17; therefore, take your monthly payment and divde that by 2.17. (Eg. a $400 monthly payment could be calculated as 400/2.17 = $184.11 bi-weekly.) With this in mind, understand that bi-weekly payments only give you the false impression that you are saving money. In an annual period it will still be the same cost.