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CD Calculator

CD APR Calculator

Convert an advertised CD APY back to its APR.

At maturity
$10,460.00
Interest
$460.00
Your CD
$
%

Rate is quoted as

mo

1 year

Common terms

Compounding frequency

Value at maturity
$10,460.00
Total interest earned
$460.00
Nominal APR
4.50%

$10,000.00 in a 1 year CD at 4.60% APY, compounded daily, grows to $10,460.00 — that’s $460.00 of interest, averaging $38.33 per month.

Balance over the term

PrincipalInterest
View the figures as a table
Balance over the term
MonthPrincipalInterestBalance
At opening$10,000.00$0.00$10,000.00
2mo$10,000.00$75.24$10,075.24
5mo$10,000.00$189.16$10,189.16
7mo$10,000.00$265.82$10,265.82
10mo$10,000.00$381.89$10,381.89
1y$10,000.00$460.00$10,460.00

Calculated in your browser using A = P(1 + r/n)nt. Nothing is sent to a server. Figures are before tax; confirm exact terms with your bank.

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  • Updates as you type
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Formulas and content last reviewed . Bank rates change frequently — confirm current rates directly with your institution.

The short answer

How do you calculate APR on a CD?

A CD's APR is its nominal annual rate before compounding — the rate actually applied at each compounding period — and it converts from APY as APR = n × ((1 + APY)^(1/n) − 1). A 4.60% APY compounded daily corresponds to a 4.50% APR. You need this conversion whenever a bank quotes you a nominal or "interest rate" figure rather than APY, because entering a nominal rate into a calculator expecting APY applies compounding twice and overstates your return. It also matters when comparing a CD against a product quoted in APR, such as a loan you might otherwise pay down. APR is always the lower of the two numbers on any account compounding more than once a year, which is why marketing leads with APY, and why Regulation DD makes APY the required disclosure.

Formula & method

How it's calculated

APR = n × ((1 + APY)^(1/n) − 1)

Strips the compounding effect back out of an advertised yield.

APR
Nominal annual rate, before compounding
APY
Advertised annual percentage yield, as a decimal
n
Compounding periods per year

Step by step

  1. 1

    Convert the advertised APY to a decimal (4.60% → 0.046).

  2. 2

    Add 1 to get the annual growth factor.

  3. 3

    Take the n-th root — raise it to the power of 1 ÷ n.

  4. 4

    Subtract 1 to get the rate for a single compounding period.

  5. 5

    Multiply by n and by 100 for the annualised nominal rate.

Guide

How to use this calculator

Four inputs, live results. Nothing to submit and nothing to sign up for.
  1. 1

    Enter the advertised rate

    Type the bank's quoted figure and set the toggle to APY, which is how deposit rates are normally published.

  2. 2

    Match the compounding frequency

    This drives the conversion. Daily compounding creates the largest gap between APY and APR.

  3. 3

    Read both rates

    The result card shows APY and APR together, so you can see precisely what compounding contributes.

Examples

Worked examples

Real numbers, worked all the way through — so you can sanity-check the calculator against your own figures.

Converting a 4.60% APY quote on a daily-compounding CD

Inputs

Advertised
4.60% APY
Compounding
Daily (n = 365)

Result

Nominal APR
4.50%
Contributed by compounding
0.10 pts

The bank credits interest at a 4.50% annual rate; daily compounding is what lifts the effective yield to 4.60%.

Methodology

Accuracy & assumptions

Every calculator makes assumptions. Here are ours, stated plainly, so you know exactly what the numbers do and do not account for.
  • APR here means the nominal deposit rate. On loans, APR also includes fees — that is a different calculation entirely.

  • The conversion assumes interest compounds at the stated frequency and stays in the account.

  • A 365-day year is used, consistent with Regulation DD.

Conventions follow Regulation DD (12 CFR 1030), which governs how US institutions disclose APY on deposit accounts. Deposits at insured institutions are FDIC-protected up to $250,000 per depositor, per bank, per ownership category.

Primary sources

Where these rules come from

The conventions this calculator follows are set by regulators, not by us. Each one links to the issuing body so you can check it rather than take our word for it.

Details

Key details and rules

Scannable facts worth knowing before you open or renew a CD.
  • For deposits, APY > APR whenever interest compounds more than once a year. For loans the relationship is reversed in effect, because fees inflate loan APR.

  • If a bank quotes only an 'interest rate' with no APY label, treat it as the nominal APR and convert before comparing.

  • The APY–APR gap scales with the rate: about 0.01 points at 1%, roughly 0.13 points at 5%.

  • If your CD pays interest out monthly rather than compounding it, your realised return matches the APR, not the APY.

Applications

Who this calculator is for

  • Detail-oriented savers

    You want to know the mechanics behind the advertised number rather than take it at face value.

  • Spreadsheet modellers

    You are building your own projection and need the nominal rate to feed a period-by-period model.

FAQs

CD APR Calculator FAQs

Direct answers to the questions asked most about this calculation. More on the FAQ hub.
  • APR = n × ((1 + APY)^(1/n) − 1), where APY is the quoted yield as a decimal and n is the number of compounding periods per year. It converts an effective annual yield back into the nominal rate that is actually applied at each compounding period. A 4.60% APY compounded daily corresponds to a 4.50% APR. You need this conversion whenever a bank hands you an APY but a calculator, a spreadsheet or a comparison expects a nominal rate — entering an APY where a nominal rate belongs applies compounding a second time and overstates the result. APR is always the lower of the two figures on any account compounding more than once a year, and the gap widens as the rate and the compounding frequency rise. It is the rate the bank works with internally; APY is the rate it advertises.

Security & privacy

Your numbers never leave your browser

Every calculation on this site runs as JavaScript on your own device. There is no account, no server call, and no analytics attached to the figures you enter.
  • Bank-standard formulas

    Uses the same compound interest and APY conventions as banks under Regulation DD.

  • 100% free, no login

    No signup, no email wall, no paywall. Every calculator is fully usable on first visit.

  • Your data never leaves your browser

    Every calculation runs client-side in JavaScript. Nothing is sent to a server or stored.

Served over HTTPS with no mixed content. Read our privacy policy or see the formulas and methodology behind every figure.

See the rate behind the rate

Every advertised APY has a nominal APR underneath it. Convert yours and see exactly what compounding is adding.