APY Calculator. Savings, CD and Interest Growth
What does your savings rate really earn?
Turn a stated interest rate into its APY, and see how a savings account or CD could grow with compounding and regular deposits.
- Free, no sign-up
- Runs in your browser
- Shareable results
- Educational only
Enter your numbers.
The amount you deposit at the start.
The rate your bank or CD quotes.
Choose APY if the rate already includes compounding.
How often interest is added. Only used for an APR.
Whole years, from 1 to 50.
What you add each month. Enter 0 for a one-off deposit or a CD.
These are hypothetical assumptions for learning, not forecasts or advice.
Result
Your balance and what you put in.
View the year-by-year table
What the numbers mean.
APY includes compounding.
APY is the yearly return after interest is added to the balance and earns interest itself. It is the fairest way to compare accounts.
More frequent compounding adds a little.
Daily compounding earns slightly more than monthly or annual at the same stated rate, but the difference is small.
Rates change.
Savings rates are usually variable and CD rates are fixed for a term. Check the current offer and any penalties before you commit.
About this apy calculator.
An APY calculator turns a stated interest rate into the yield you actually earn and shows how a deposit grows. Enter a starting deposit, the rate, whether it is an APR or already an APY, how often it compounds, the number of years and any monthly deposits. The calculator returns the APY, the ending balance, the interest earned and the years to double.
APY is the right number for comparing savings accounts and CDs, because it includes interest earning interest. See compound interest examples for how that builds up, and use the compound interest calculator for investments, the savings goal calculator to turn a target into a monthly figure, or the real return calculator to see growth after inflation.
How the apy calculator works in practice.
Using the default inputs: starting deposit $10,000; stated interest rate 4.5%; type of rate: apr: stated rate, compounded; compounding: monthly; years 5 years; monthly deposit $0.
Annual percentage yield (APY): 4.59%
Interest earned: $2,518
Total you deposit: $10,000
Interest in year 1: $459.40
Years to double: 15.4
Interest as a share of the balance: 20.11%
With the “High-yield (5%)” preset, balance after 5 years: $12,834. With the “Low rate (1%)” preset, balance after 5 years: $10,512. With the “Adding $200 a month” preset, balance after 5 years: $25,947. Change one input at a time to see which assumption matters most.
How to choose your inputs for the apy calculator.
Starting deposit. The amount you deposit at the start.
Stated interest rate. The rate your bank or CD quotes.
Type of rate. Choose APY if the rate already includes compounding.
Compounding. How often interest is added. Only used for an APR.
Years. Whole years, from 1 to 50.
Monthly deposit. What you add each month. Enter 0 for a one-off deposit or a CD.
How the apy calculator works.
If you enter an APR, the calculator converts it to an APY using the compounding frequency. It then grows your deposit month by month at that effective rate, adding your monthly deposits at month-end.
Monthly rate = (1 + APY)^(1 ÷ 12) − 1
Balance next month = balance × (1 + monthly rate) + monthly deposit
Interest earned = ending balance − total deposited
The model assumes a rate that stays fixed for the whole period. Taxes, fees, minimum balances and changes in the rate are not modeled, and interest is shown before tax.
Limits of this apy calculator.
The calculator assumes the rate stays fixed for the whole period. Savings account rates usually change, and CDs can carry early-withdrawal penalties and minimum deposits. Interest is shown before tax, and fees and the effect of inflation are not included. Treat the result as an illustration of compounding, not a quote from any bank.
Common questions about the apy calculator.
What is APY?
APY, or annual percentage yield, is the effective yearly return on a deposit after compounding. It lets you compare accounts that compound at different frequencies.
What is the difference between APR and APY?
APR is the stated rate before compounding. APY includes the effect of interest earning interest, so it is slightly higher than the APR when interest compounds more than once a year.
How do I calculate APY?
Divide the APR by the number of compounding periods per year, add 1, raise it to the power of the number of periods, then subtract 1. The calculator does this for you.
How much interest will a CD earn?
Enter the deposit, the CD’s rate and its term in years, with no monthly deposits. The calculator shows the interest earned over the term.
Is the interest taxable?
In many countries, yes. Tax rules depend on your country and account type, and this calculator shows interest before tax.
More calculators.
Educational illustration only, not a forecast or personal investment recommendation. Results depend entirely on the assumptions entered.
Further learning: Glossary · Investor.gov: Financial tools and calculators · Research methodology · Financial disclaimer