Savings & CDs

APY Calculator

Convert between a nominal annual deposit rate and APY. Choose how often interest compounds to see the equivalent rate and compare five frequencies.

Equivalent APY(Example)

5.1162%

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Conversion direction

Compounding frequency

For deposit interest rates. Fee-bearing loan APRs are not supported. The 100% limit applies to your input; a calculated APY can be higher.

Equivalent APY

5.1162%

Example calculation · not a bank offer

Nominal annual interest rate: 5%
Compounding frequency: Monthly (12/year)

Assumes a fixed rate and reinvested interest for one year. Results are rounded to 4 decimal places; fees and taxes are excluded.

Transfers your original rate, rate type, and frequency once in this tab. You will enter the deposit amount and term in the CD calculator. This is an assumption, not a bank offer.

Your rate is calculated in browser memory and is not sent to a server. The optional CD transfer expires after one minute or when used. Reloading or returning here does not restore your inputs.

See formulas and assumptions

Compare compounding frequencies

Each row uses your same nominal annual interest rate. More frequent compounding increases APY when the rate is positive and interest stays in the account.

Compare compounding frequencies
Compounding frequency	Annual percentage yield (APY)
Annually (1/year)	5%
Semiannually (2/year)	5.0625%
Quarterly (4/year)	5.0945%
Monthly (12/year)Selected	5.1162%
Daily (365/year)	5.1267%

Estimate a deposit’s balance and interest with the CD calculator →

How to convert interest rates and APY

APY includes compounding; a nominal annual deposit interest rate does not. For a fixed rate, the formulas below translate between the two using the number of compounding periods per year.

Nominal interest rate to APY

a = (1 + r/n)^n − 1

Here r is the nominal annual rate as a decimal, a is APY as a decimal, and n is the number of compounding periods per year. Divide a percentage by 100 before using it in the formula, then multiply the answer by 100.

For 5% nominal interest compounded monthly: (1 + 0.05/12)^12 − 1 = 0.0511618979, or about 5.1162% APY.

CFPB: definitions of APY and deposit interest rate

APY to nominal interest rate

r = n × ((1 + a)^(1/n) − 1)

To work backward, start with APY as a decimal and choose the account’s compounding frequency. Different frequencies can produce the same APY from different nominal rates.

For 5% APY with monthly compounding: 12 × ((1 + 0.05)^(1/12) − 1) = 0.0488894854, or about 4.8889% nominal interest.

APY vs. APR: check what the rate means

A nominal deposit rate may also be labeled APR, but loan APR is a different disclosure and can include borrowing fees and other charges. This tool converts a nominal deposit rate using compounding only. It cannot calculate the cost of a loan or convert a fee-bearing loan APR into a deposit APY.

CFPB: loan interest rates and APR

What this estimate assumes

The rate stays fixed for one year and all interest remains in the account. Daily means 365 equal periods; other options use 1, 2, 4, or 12 periods per year. Fees, taxes, withdrawals, variable rates, promotional tiers, and bank-specific rounding are not modeled. Check the account’s disclosed APY and terms for an actual offer.

APY questions

Is APY always higher than the nominal interest rate?

With a positive rate and more than one compounding period per year, APY is higher if interest is reinvested. With annual compounding, or a zero rate, they are equal under this model.

Should I compound an advertised APY again?

No. APY already includes compounding. Use APY mode here to find an equivalent nominal rate, or enter the advertised APY directly in the CD calculator to estimate a balance.

Why can my converted rate look slightly different from a bank’s?

A bank may round its displayed rate or APY and apply specific day-count, crediting, balance, or promotional terms. This calculator uses your entered rate and the stated equal-period model. Displayed results are rounded, so re-entering one may not reproduce every original decimal.