APR, APY and Interest Rates: Compare Financial Offers Without Mixing the Measures

Two offers can advertise different percentages because they are measuring different things. A borrowing APR, a loan's stated interest rate and a deposit APY are not interchangeable labels. Understanding the calculation behind each figure can prevent a seemingly cheap loan or attractive savings account from being judged on the wrong basis. Start with the product and the disclosure, then compare like with like.

The stated loan rate is only one input

A loan's interest rate describes the interest cost under the agreement. It does not necessarily include all charges paid to obtain the loan. Origination fees and other relevant costs can make borrowing more expensive than the stated rate suggests. The exact treatment of fees depends on the product and disclosure rules. Ask for the formal documents rather than relying on a verbal quote. A low rate paired with substantial upfront costs can be less appealing for a borrower who expects to repay or refinance quickly.

APR helps organize borrowing costs

Annual percentage rate expresses a borrowing-cost measure that includes interest and certain fees under the applicable rules. It can improve comparisons, but it is not a universal total-cost guarantee. Compare the same product type, term, amount and assumptions. A longer loan may have a lower payment while costing more over time. A variable-rate product adds uncertainty about future costs. Do not compare one lender's interest rate with another lender's APR and conclude that the smaller percentage necessarily represents the cheaper offer.

APY accounts for deposit compounding

Annual percentage yield describes the annualized effect of a deposit rate and compounding under specified assumptions. It helps compare interest-bearing accounts, but fees and balance conditions still matter. In an illustrative example, a 4% nominal annual rate compounded monthly produces an effective annual yield slightly above 4% if the assumptions hold. That is a calculation example, not an available offer. A promotional APY may apply only for a limited period or to eligible balances, so read what happens when the promotion ends.