The Annual Percentage Rate (APR) is the annualized interest rate that you are charged on a loan, credit card, or other line of credit. It is the rate used to calculate monthly payments.How is APR calculated?APR is calculated by taking the daily periodic rate and multiplying it by the number of days in the year. The daily periodic rate is simply the interest rate divided by 365 days.What factors affect APR?There are a few factors that affect the size of the APR on a loan, credit card, or other line of credit. The most important factor is the interest rate, but other factors can include fees, charges, and the length of time over which interest is charged.How can I compare APRs?When comparing APRs between different lenders, be sure to look at the total costs of borrowing over time. This includes not only the interest charges, but also any fees or other charges that may apply.