How do you calculate the cost of paying a life insurance premium monthly instead of annually?  Get a Rate Calculator from  Put the annual premium in the Present Value as a negative number (which changes it to Loan Balance) since the insurance company is loaning you the annual premium and you pay them back monthly.  Then make the mode “monthly” and “beg” for beginning of year since the insurance company loans you money at the beginning of the period.  Put the monthly premium payment in Monthly Payment box and the Months as 12.  In the following example, the interest charge the company assesses you for paying monthly is 6.5%.