How to calculate APY on a CD?

You calculate a CD's APY with APY = (1 + r/n)^n − 1, where r is the nominal annual rate the bank applies each compounding period, and n is how many times per year that happens. The formula converts a rate that compounds during the year into one effective annual figure, because a nominal rate alone does not show how much compounding adds — two CDs with the same nominal rate but different compounding frequencies pay different amounts, and APY makes that difference visible. Divide the nominal rate by n, add 1, raise the result to the power of n, then subtract 1 and multiply by 100 to express it as a percentage. A 4.41% nominal rate compounded daily works out to 4.51% APY, meaning daily compounding alone contributes about 0.10 percentage points beyond the stated nominal rate. This is why Regulation DD requires US banks to disclose APY — it is the only figure that lets you compare two CDs regardless of how often each compounds.

What is the difference between APY and interest rate on a CD?

The interest rate on a CD, sometimes labelled the nominal rate or APR, is the figure the bank applies at each compounding period before that compounding effect is factored in; APY is the resulting effective annual yield after it is. The gap exists because compounding means interest earns interest during the term, and the nominal rate alone does not capture that extra growth, while APY is calculated specifically to include it: APY = (1 + r/n)^n − 1. On a CD paying a 4.40% nominal rate compounded daily, the nominal figure alone would suggest $10,440.00 in growth on $10,000 over a year, but the actual maturity value is $10,449.80, and that higher figure is what the 4.4980% APY reflects. APY is always equal to or greater than the nominal rate for any account compounding more than once a year, and it is the number to compare across banks, since one institution's nominal rate and another's APY are not directly comparable.

Does a higher compounding frequency always mean a higher APY?

Yes, for a fixed nominal rate, more frequent compounding always produces a higher APY, because APY = (1 + r/n)^n − 1 increases as n increases — daily compounding (n = 365) beats monthly (n = 12), which beats quarterly (n = 4) and annual (n = 1) at the same underlying rate. The mechanism is that more frequent compounding credits interest sooner, so that interest itself starts earning interest sooner too, and those small early gains stack up across the year. In dollar terms the effect is real but modest: a $10,000 deposit at a 4.40% nominal rate compounded daily matures at $10,449.80 over 12 months, compared with $10,440.00 if the same rate compounded only once a year — a $9.80 difference from frequency alone. Because the gain from higher frequency shrinks the more often you already compound, the jump from annual to monthly matters more than monthly to daily, so the headline rate remains the dominant factor.

CD APY Calculator

어떤 CD 금리든 실제 연 수익률로 환산합니다.

Convert any CD rate into its true annual percentage yield and compare offers on equal footing.

만기 시: US$15,637.50
이자: US$637.50

내 예금증서

예치 금액

이자율

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기간

개월

1 년

일반적인 기간

복리 주기

만기 금액: US$15,637.50
총 이자 수익: US$637.50
실효 APY: 4.25%

1 년 예금증서에 US$15,000.00, 금리 4.25% APY, 일 복리 복리로 US$15,637.50까지 증가 — 이자 US$637.50, 월평균 US$53.13입니다.

기간 중 잔액

원금이자

수치를 표로 보기

기간 중 잔액
개월	원금	이자	잔액
개설 시	US$15,000.00	US$0.00	US$15,000.00
2mo	US$15,000.00	US$104.42	US$15,104.42
5mo	US$15,000.00	US$262.40	US$15,262.40
7mo	US$15,000.00	US$368.65	US$15,368.65
10mo	US$15,000.00	US$529.40	US$15,529.40
1y	US$15,000.00	US$637.50	US$15,637.50

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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공식과 내용 최종 검토일 2026년 7월 21일. 은행 금리는 자주 바뀝니다. 현재 금리는 거래 기관에 직접 확인하십시오.

짧은 답변

CD의 APY는 어떻게 계산하나요?

APY is the effective annual yield after compounding is applied, calculated as APY = (1 + r/n)^n − 1, where r is the nominal annual rate and n is the number of compounding periods per year. A 4.40% nominal rate compounded daily works out to 4.50% APY. The gap between the two widens as n rises and as the rate rises, which is precisely why Regulation DD requires US institutions to disclose APY: it collapses rate and compounding frequency into one number that can be compared across banks. Two CDs quoting the same nominal rate but compounding daily versus annually are not the same product, and only the APY shows it. On a term of exactly one year, APY and the actual percentage gain are identical — $10,000 at 4.50% APY returns $10,450.00, a gain of exactly 4.50%.

공식과 방법

계산 방법

APY = (1 + r/n)^n − 1

Converts a nominal rate into the effective yield you actually earn over a year.

APY: Annual percentage yield — the effective rate
r: Nominal annual rate as a decimal
n: Compounding periods per year

단계별 계산

1
Convert the nominal rate to a decimal (4.41% → 0.0441).
2
Divide it by the compounding periods per year (daily → 365).
3
Add 1 to the result.
4
Raise that to the power of n.
5
Subtract 1 and multiply by 100 to express it as a percentage.

가이드

이 계산기 사용법

네 가지 값만 넣으면 결과가 바로 나옵니다. 제출할 것도, 가입할 것도 없습니다.

1
Enter the quoted rate
Type the rate exactly as the bank publishes it, then set the toggle to APR if it is a nominal rate.
2
Set the compounding frequency
This is what separates APR from APY. Daily compounding produces the highest APY for the same nominal rate.
3
Read the effective APY
The result card shows both the nominal rate and the effective APY side by side, so the compounding premium is visible.
4
Compare offers
Convert every competing offer to APY, then compare. This is the only apples-to-apples comparison.

예시

계산 예시

실제 숫자로 끝까지 풀어 본 예시입니다. 직접 넣으신 값과 대조해 계산기가 맞는지 확인해 보십시오.

A 4.41% nominal rate compounded daily

Nominal rate (APR): 4.41%
Compounding: Daily (n = 365)

Effective APY: 4.51%
Compounding premium: +0.10 pts

Daily compounding turns 4.41% into 4.51% — which is why banks advertise APY, and why comparing an APY to an APR flatters the APR offer.

계산 방법

정확성과 가정

모든 계산기는 어떤 가정 위에서 움직입니다. 이 숫자가 무엇을 반영하고 무엇을 반영하지 않는지 그대로 밝혀 둡니다.

The rate holds for the full year and interest stays in the account to compound.
APY assumes a 365-day year, per Regulation DD.
For terms shorter than a year, APY is still the annualised figure — you earn a pro-rated share of it.

계산 관행은 미국 금융기관이 예금 계좌의 APY를 공시하는 방식을 규정한 Regulation DD(12 CFR 1030)를 따릅니다. 예금자보호 대상 기관의 예금은 예금자별, 은행별, 소유 형태별로 $250,000까지 FDIC의 보호를 받습니다.

1차 자료

이 규칙은 어디에서 왔나

이 계산기가 따르는 관행은 저희가 아니라 규제 기관이 정합니다. 각 항목은 해당 기관으로 연결되므로 저희 말을 믿는 대신 직접 확인하실 수 있습니다.

세부 사항

핵심 내용과 규칙

CD에 가입하거나 재예치하기 전에 알아 둘 만한 사실을 한눈에 정리했습니다.

APY includes compounding; APR does not. For any n greater than 1, APY is always higher than APR.
US banks are required by Regulation DD (12 CFR 1030) to disclose APY on deposit accounts, so it is always available.
The gap between APR and APY widens as rates rise — at 1% it is negligible, at 5% it is worth roughly 0.13 points.
If interest is paid out instead of compounded, your realised yield equals the nominal rate, not the APY.

서로의 관계

이 계산기가 필요한 분

Cross-bank comparers
One bank quotes APY, another quotes a nominal rate, and you need them on the same scale.
Yield-focused savers
You want the highest effective return and need to see what compounding frequency is actually adding.

모든 CD 계산기

정기예금(CD)의 모든 측면을 다루는 아홉 개의 계산기입니다.

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