Understanding the difference between APR and APY is essential when evaluating loans, credit cards, savings accounts, or investment options. Both terms represent interest rates but serve different purposes and calculations.

Annual Percentage Rate (APR) represents the yearly cost of borrowing money or the annualized rate charged on loans, credit cards, or mortgages. APR includes the interest rate plus any additional fees or costs associated with the loan, but it does not account for compounding within the year. This makes APR useful for comparing different loan offers since it reflects the straightforward cost of borrowing.

For example, a credit card or car loan with a 6% APR means you will pay 6% of the loan amount in interest annually, not including the effect of compounding interest.

Annual Percentage Yield (APY), sometimes called effective annual rate (EAR), calculates the actual return on an investment or cost of borrowing by considering compounding interest over the year. It assumes that interest is reinvested and earns additional interest, which means APY provides a more accurate picture of the true rate earned or paid.

For instance, a savings account advertised with a 5% APY reflects what you will realistically earn after compounding, making it a more precise measurement of growth than a simple interest rate.

Why APR and APY Matter

  • APR is key for borrowers who want to understand the total yearly cost of a loan or credit card.
  • APY benefits savers and investors by revealing the real rate of return over time, including interest on interest.

How to calculate APR and APY

  • APR calculation is usually provided by lenders and includes interest plus fees, expressed as an annual rate. It does not compound, so the rate remains the same throughout the year.

  • APY can be calculated using the formula:

    [ \text{APY} = \left(1 + \frac{r}{n}\right)^n – 1 ]

    where (r) is the annual interest rate and (n) is the number of compounding periods per year.

Practical Example

Consider a loan with an APR of 6%, compounded monthly. Its APY would be slightly higher because interest compounds each month:

[ \text{APY} = \left(1 + \frac{0.06}{12}\right)^{12} – 1 = 0.0617 \text{ or } 6.17\% ]

This means you actually pay 6.17% over one year, factoring in compounding.

Where You Encounter APR & APY

  • APR is commonly seen with mortgages, auto loans, credit cards, and personal loans.
  • APY is typical for savings accounts, certificates of deposit (CDs), and other investment products.

Important Considerations

  • When comparing loans, use APR to estimate the cost because it includes fees.
  • When comparing savings or investment products, use APY for a true picture of growth.

For further details on these terms, see our dedicated guides on APR (Annual Percentage Rate) and Annual Percentage Yield (APY).

Authoritative Source

According to the Federal Reserve, APR does not reflect compounding, whereas APY does, which can significantly affect your financial outcomes (see ConsumerFinance.gov glossary).