Enter your rate and compound frequency to calculate APY and earnings.
APY vs APR Explained
APY is the rate you actually earn once compounding is included: APY = (1 + r/n)n − 1, where r is the stated annual rate and n the number of compounding periods a year. A 4.00% rate compounded daily is a 4.081% APY; compounded monthly it is 4.074%. Enter a rate, frequency and balance above to see the APY and the interest in dollars.
APR (Annual Percentage Rate) is the nominal interest rate without accounting for compounding. APY (Annual Percentage Yield) is the effective annual rate after compounding: it's what you actually earn. For savings and CDs, APY is always equal to or higher than APR.
For borrowing (credit cards, loans), APR is the stated cost. The effective rate you pay can be higher due to fees and compounding. This is why comparing APY-to-APY for savings and APR-to-APR for loans gives the most accurate picture.
Daily vs Monthly Compounding
The Rule of 72
Continuous Compounding
Savings vs Loan APY
APR to APY Conversion Table
Example nominal rates, not current offers. The APY rises with compounding frequency, but only slightly.
| Nominal rate | Quarterly | Monthly | Daily |
|---|---|---|---|
| 1.00% | 1.004% | 1.005% | 1.005% |
| 2.00% | 2.015% | 2.018% | 2.020% |
| 3.00% | 3.034% | 3.042% | 3.045% |
| 3.50% | 3.546% | 3.557% | 3.562% |
| 4.00% | 4.060% | 4.074% | 4.081% |
| 4.50% | 4.577% | 4.594% | 4.602% |
| 5.00% | 5.095% | 5.116% | 5.127% |
Going the other way: APY to APR
To find the nominal rate behind an advertised APY, use APR = n × ((1 + APY)1/n − 1). A 4.00% APY compounded monthly comes from a 3.928% nominal rate, and from 3.922% if compounded daily. You rarely need this for savings, since banks must quote APY, but it helps when an account or bond quotes only a nominal rate.
What an APY Earns on $10,000
Interest earned with no deposits or withdrawals. The first row is the FDIC national average savings rate for August 2026; the rest are example rates.
| APY | After 1 year | After 5 years | After 10 years |
|---|---|---|---|
| 0.38% (national average) | $38 | $191 | $387 |
| 1.00% | $100 | $510 | $1,046 |
| 2.00% | $200 | $1,041 | $2,190 |
| 3.00% | $300 | $1,593 | $3,439 |
| 4.00% | $400 | $2,167 | $4,802 |
| 5.00% | $500 | $2,763 | $6,289 |
The gap between an average account and a competitive one is far bigger than anything compounding frequency can add. Moving from daily to monthly compounding at 5% changes a year's interest on $10,000 by about $1.
Rates, Taxes and Inflation in 2026
Where rates stand
The Federal Reserve raised its federal funds target range by a quarter point to 3.75% to 4.00% in September 2026. Savings and money market APYs are variable and tend to follow that rate within weeks. CD rates are fixed once you open the CD. The FDIC's national averages for August 2026 were 0.38% for savings, 0.63% for money market accounts and 1.71% for a 12-month CD. Online banks usually pay well above those averages, so check each bank's current APY before you move money.
Your real return
Interest is taxed as ordinary income. A 4.00% APY taxed in the 22% bracket leaves 3.12%, and with consumer prices up 3.4% in the year to August 2026 (BLS CPI-U), the real return is slightly negative, about minus 0.27%. A high APY protects cash from inflation; it rarely grows it.
Rule of 72 check
Divide 72 by the APY to estimate the years it takes to double your money. At 4% that gives 18 years; the exact answer is 17.7.