DayCents

APY (Annual Percentage Yield)

APY is the real rate of return on savings over a year, including the effect of compound interest. Because it accounts for interest earning interest, APY is always equal to or higher than the stated interest rate, and it is the number to compare when shopping for savings accounts or CDs.

A 4.4% nominal rate compounded monthly produces an APY of about 4.49%. The Truth in Savings Act requires banks to advertise APY precisely so accounts can be compared on equal footing regardless of compounding frequency. Two practical notes. The gap between monthly and daily compounding is small — on a 5% rate it is about a hundredth of a percentage point — so it is not worth choosing a bank over, while a whole point of difference in the headline rate certainly is. And a savings account's APY is variable: it is what you would earn if today's rate held for a year, not a promise. Only a CD locks it for the term.