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CD & Savings Calculator

Compute interest on a Certificate of Deposit (CD) or savings account, convert a stated APR and compounding frequency into APY, compare APY across daily/monthly/quarterly/annual compounding, and project long-term compound growth with recurring contributions — all in USD, with instant, plain-English results.

4 modes CD · Savings · Compare · Ladder APY from APR + compounding Free, no sign-up Updated: Jul 27, 2026
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The amount you plan to deposit into the CD.
Quick amount
%
The nominal rate your bank advertises, before compounding.
mo
Common CD terms
The maturity date is calculated automatically from the term.
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The amount you're depositing today.
%
yrs
$
Amount you add each month (leave 0 if none).
Quick horizon
Compare the APY (and dollar growth) produced by the same stated APR at different compounding frequencies:
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%
yrs
Quick horizon
Split a total amount across CDs with staggered terms ("rungs") so part of your money becomes available on a regular schedule while the rest keeps earning CD-level rates:
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Total is split evenly; each rung's term is 1 year longer than the last.
pts
Added to the base APY for each extra year of term (typical of real CD rate ladders).
%
⚙️ Advanced — estimated tax rate & inflation-adjusted real return
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%
Tax rate is used to estimate after-tax interest on the CD calculator tab. In the US, banks generally do not withhold income tax on CD or savings interest automatically — you're responsible for reporting it on Form 1099-INT. Inflation, if entered, adds an inflation-adjusted real return estimate on the CD and Savings growth tabs.
Quick answer CD and savings interest is found with FV = P × (1 + APR/n)^(n×t), where P is your principal, APR is the stated rate, n is the compounding periods per year, and t is the term in years. The resulting effective annual rate is your APY = (1 + APR/n)^n − 1 — the number US banks are legally required to disclose. For example, $10,000 at a 5.00% APY for 1 year earns exactly $500.00 in interest.
$500$10,000 · 5.00% APY · 1 year
5.13%5.00% APR compounded daily → APY
72÷rRule of 72 doubling time
$250KFDIC insurance, per depositor/bank
⚙️ Note: This tool applies standard compound-interest math (FV = P × (1 + APR/n)^(n×t)) and the APY formula required for disclosure under the Truth in Savings Act. It does not look up live bank rates, and actual CD terms, rates, and early withdrawal penalties are set by your bank and can change. Results are for informational purposes only and are not tax, investment, or financial advice.
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How is CD and savings account interest calculated?

A complete guide — with formulas and examples — to CD interest, converting APR into APY, compounding frequency, taxes, and FDIC insurance.

A Certificate of Deposit (CD) is a fixed-term deposit account: you agree to leave your money with a bank for a set term — commonly 3 months, 6 months, 1 year, 2 years, or 5 years — in exchange for a fixed interest rate that usually beats a regular savings account. A savings account, by contrast, gives you ongoing access to your money at a variable rate. Both pay compound interest, and both are required by federal law to disclose their Annual Percentage Yield (APY) so you can compare offers on equal footing. The calculator above handles CD interest, long-term savings growth with recurring contributions, and a side-by-side comparison of how compounding frequency changes your APY.

How do you calculate CD interest from a stated APR?

Quick answerFuture value is FV = P × (1 + APR/n)^(n×t), where P is your principal, APR is the stated annual rate, n is the number of compounding periods per year, and t is the term in years. Interest earned is FV − P. For example, $10,000 at a 5.00% APR compounded daily (n=365) for 1 year grows to about $10,512.68, for $512.68 in interest.
  • Principal (P): the amount you deposit; interest is calculated on this base (plus any interest already added, once compounding occurs).
  • APR: the stated, nominal annual rate before compounding is factored in.
  • Compounding frequency (n): how often interest is calculated and added to the balance — daily, monthly, quarterly, or annually.

What is APY, and how is it different from APR?

Quick answerAPY (Annual Percentage Yield) is the effective annual return once compounding is included: APY = (1 + APR/n)^n − 1. APR is just the stated, nominal rate before compounding. APY is always equal to or greater than APR (equal only when compounded once a year). Under the Truth in Savings Act, US banks must disclose APY on deposit accounts precisely so customers can compare rates fairly, regardless of how often each bank compounds interest.

This matters because two accounts advertising the "same" 5.00% rate can pay differently: a 5.00% APR compounded annually is a 5.00% APY, but the same 5.00% APR compounded daily is a 5.13% APY. Always compare accounts by APY, not by the raw stated rate, since compounding schedules vary from bank to bank.

How much does compounding frequency change your return?

For a $10,000 deposit at a 5.00% stated APR over 1 year: annual compounding yields $10,500.00 (5.00% APY), quarterly compounding yields $10,509.45 (5.09% APY), monthly compounding yields $10,511.62 (5.11% APY), and daily compounding yields $10,512.68 (5.13% APY). The gains shrink as compounding gets more frequent — the jump from annual to monthly is far larger than the jump from monthly to daily. See the "APY by compounding" tab above, or the reference table further down this page, for the full comparison.

Is CD and savings account interest taxable?

Quick answerYes. The IRS treats CD and savings interest as ordinary taxable income in the year it's earned or credited, even if you don't withdraw it. Your bank reports it to you and the IRS on Form 1099-INT if it's $10 or more. Unlike payroll, banks generally do not withhold income tax on interest automatically — you're responsible for reporting and paying tax on it yourself.

Enter an estimated combined federal + state tax rate under "Advanced settings" on the CD tab to see an estimate of your after-tax interest. This calculator's tax estimate is informational only; consult a tax professional for your specific situation.

What's the difference between simple interest and compound interest?

Quick answerSimple interest is calculated only on the original principal: Value = P × (1 + r × t). Compound interest is calculated on the principal plus all interest already earned: Value = P × (1 + r/n)^(n×t). Over short periods the gap is small, but it widens quickly: $10,000 at 5% for 20 years grows to $20,000 with simple interest, but to roughly $26,533 with annual compounding.

Are CDs FDIC insured, and what about early withdrawal?

Quick answerYes — CDs and savings accounts at FDIC-member banks are insured up to $250,000 per depositor, per bank, per ownership category (credit unions carry equivalent NCUA coverage). The trade-off for a CD's typically higher rate is reduced access: withdrawing before the maturity date usually triggers an early withdrawal penalty, often a forfeiture of several months' interest, and in extreme cases that penalty can even dip into your principal.

How much does a $10,000 CD earn? (examples by term)

$10,000 at a 5.00% APY across common CD terms. For your own rate and amount, use the calculator above.

$10,000 CD — interest and total at maturity by term (5.00% APY)
TermInterest earnedTotal at maturity
3-month$122.72$10,122.72
6-month$246.94$10,246.94
1-year$500.00$10,500.00
2-year$1,025.00$11,025.00
5-year$2,762.82$12,762.82

Note: this table shows a single-term deposit compounding continuously at a fixed 5.00% APY. If you renew ("roll over") the CD at maturity, the same compounding effect continues into the next term.

Popular calculations

Related mini calculators: savings goal, APY↔APR, Rule of 72, and early withdrawal

Four fast, standalone tools: how long until you hit a savings target, converting a known APY back into APR, the classic "Rule of 72" doubling-time estimate, and whether breaking a CD early is worth it.

🎯Savings goal calculator
Find out how many years it takes your balance to reach a target amount at a given APY (compounded annually, no added contributions).
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$
🔁APY to APR converter
Back out the nominal, pre-compounding APR from a known APY and compounding frequency.
⏳Rule of 72 — doubling time
A quick mental-math estimate for how many years it takes your money to double at a given annual rate.
⛔Early withdrawal penalty calculator
Enter your CD and penalty terms to compare breaking it today versus holding it to maturity.
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CD & savings reference tables

Citable reference tables: interest by APY, by deposit amount, APY by compounding frequency, and an early-withdrawal-penalty example.

$10,000, 1-year term — interest by APY
APYInterest (1 yr)Total at maturity
4.00%$400.00$10,400.00
4.50%$450.00$10,450.00
5.00%$500.00$10,500.00
5.50%$550.00$10,550.00

Over exactly one year, interest earned = principal × APY, since APY is already the effective annual return.

5.00% APY, 1-year term — interest by deposit amount
DepositInterest (1 yr)Total at maturity
$1,000$50.00$1,050.00
$5,000$250.00$5,250.00
$10,000$500.00$10,500.00
$25,000$1,250.00$26,250.00
$50,000$2,500.00$52,500.00

Interest scales linearly with the deposit amount for a fixed APY and term.

$10,000, 5.00% stated APR, 1 year — APY by compounding frequency
CompoundingPeriods/yrResulting APYTotal after 1 yr
Annually15.00%$10,500.00
Quarterly45.09%$10,509.45
Monthly125.11%$10,511.62
Daily3655.13%$10,512.68

Same 5.00% stated APR — more frequent compounding produces a higher APY, but the improvement shrinks as frequency increases.

$10,000, 1-year CD at 5.00% APY — illustrative 90-day early withdrawal penalty
Withdrawal timingInterest accruedPenalty (90 days' interest)Net proceeds
At 3 months (early)$122.72−$123.29$9,999.43
At 6 months (early)$246.94−$123.29$10,123.65
At 9 months (early)$372.72−$123.29$10,249.43
At 12 months (maturity)$500.00$0.00$10,500.00

Illustrative example using a representative 90-day-interest penalty. Notice that withdrawing very early can leave you with slightly less than your original principal. Actual penalty terms vary by bank and CD length — always check your CD's disclosure before opening it.

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CD & interest terms glossary

Short definitions of the core terms used throughout this calculator.

Certificate of Deposit (CD)A fixed-term deposit account paying a set rate in exchange for leaving your money untouched until maturity.
PrincipalThe amount you deposit; the base on which interest is calculated.
APY (Annual Percentage Yield)The effective annual return including compounding: APY = (1 + APR/n)^n − 1. Required by law to be disclosed.
APR / nominal rateThe stated annual interest rate before accounting for compounding.
Compounding frequencyHow often interest is calculated and added to the balance: daily, monthly, quarterly, or annually.
Maturity dateThe date a CD's term ends, when you can withdraw principal and interest without penalty.
Early withdrawal penaltyA fee, often a forfeiture of some interest, charged for taking money out of a CD before maturity.
Truth in Savings ActThe federal law requiring banks to disclose APY on deposit accounts, so consumers can compare rates fairly.
FDIC insuranceFederal deposit insurance covering up to $250,000 per depositor, per bank, per ownership category.
CD ladderA strategy of splitting savings across CDs with staggered maturity dates for periodic access plus CD-level rates.
Future Value (FV)The value an investment grows to after a given time, accounting for interest.
Rule of 72A quick estimate for doubling time: divide 72 by the annual interest rate (in percent).

In-depth guides

Step-by-step explanations of the most commonly confused CD and savings questions.

How much does a $10,000 CD actually earn? (step by step)

Step 1: Find your APY — either use the rate your bank discloses directly, or compute it from the stated APR and compounding frequency: APY = (1 + APR/n)^n − 1.
Step 2: Convert your term to years (e.g., 6 months = 0.5 years).
Step 3: Apply FV = P × (1 + APY)^t. For $10,000 at 5.00% APY over 6 months: FV = 10,000 × 1.05^0.5 = $10,246.94, so interest earned is $246.94.
Step 4: Interpret — at maturity you'd receive $10,246.94 total: your original $10,000 plus $246.94 in interest, before any tax you may owe on that interest.

APY vs APR: why compounding frequency changes what you actually earn

Two CDs can advertise the "same" 5.00% rate and still pay differently, because one bank might compound daily while another compounds only annually. A 5.00% APR compounded annually produces exactly a 5.00% APY — no benefit from compounding, since interest is only added once a year. The same 5.00% APR compounded daily produces roughly a 5.13% APY, because interest is calculated on a slightly larger balance every single day.

This is exactly why the federal Truth in Savings Act requires banks to disclose APY rather than just the raw stated rate — it lets you compare offers apples-to-apples no matter how each bank structures its compounding. When shopping for a CD or savings account, always compare the APY, and use the "APY by compounding" tab above to see how a single stated rate changes at different compounding frequencies.

Is your savings account beating inflation? Real vs. nominal returns

Your nominal return is simply the dollar growth your APY produces. Your real return adjusts that growth for inflation, reflecting the change in your actual purchasing power: Real return ≈ ((1 + nominal return) ÷ (1 + inflation)) − 1. For example, a 4.50% APY with 3.00% inflation gives a real return of about +1.46% — your money is genuinely growing, just more slowly than the nominal rate suggests.

If inflation exceeds your APY, your real return turns negative: your account balance still grows in dollar terms, but it buys less than it used to. Enter a rate under "Annual inflation rate" in Advanced settings to see this real-return estimate alongside your nominal results on the CD and Savings growth tabs.

Frequently asked questions

How is CD interest calculated?
CD interest uses the compound-interest formula: FV = P × (1 + APR/n)^(n×t), where P is principal, APR is the stated rate, n is compounding periods per year, and t is the term in years. Interest earned is FV − P. If you already know the APY, use FV = P × (1 + APY)^t instead. For example, $10,000 at a 5.00% APY for 1 year earns exactly $500.00 in interest.
What is the difference between APR and APY?
APR is the stated, nominal rate before compounding. APY is the effective annual return once compounding is included: APY = (1 + APR/n)^n − 1. APY is always equal to or higher than APR. The Truth in Savings Act requires US banks to disclose APY so you can compare accounts fairly, regardless of each bank's compounding schedule.
What is compound interest, and why does it matter for CDs and savings?
Compound interest is interest calculated on your principal plus the interest you've already earned — "interest on interest." More frequent compounding (daily vs. monthly vs. annually) grows your balance faster, though the added benefit shrinks as frequency increases. Over long horizons, compounding produces significantly more growth than simple interest, which only ever applies to the original principal.
How much does a $10,000 CD earn in a year?
At a 5.00% APY, a $10,000 CD earns $500.00 in interest over one year, for a total of $10,500.00 at maturity. The amount scales directly with APY over exactly one year — a 4.50% APY earns $450.00 and a 5.50% APY earns $550.00 — since one-year interest equals principal × APY.
Is CD and savings account interest taxable?
Yes. The IRS taxes CD and savings interest as ordinary income in the year it's earned, even if you don't withdraw it, and your bank reports it on Form 1099-INT if it's $10 or more. Unlike wages, banks generally don't withhold income tax on interest automatically — you're responsible for reporting it. Use the "Estimated tax rate" field to see an after-tax estimate.
What's the difference between simple interest and compound interest?
Simple interest: Value = P × (1 + r × t), calculated only on the original principal. Compound interest: Value = P × (1 + r/n)^(n×t), calculated on principal plus previously earned interest. Over short periods the gap is small, but $10,000 at 5% for 20 years grows to $20,000 with simple interest versus roughly $26,533 with annual compounding.
Are CDs FDIC insured?
Yes — CDs and savings accounts at FDIC-member banks are insured up to $250,000 per depositor, per bank, per ownership category (credit unions carry equivalent NCUA coverage). This makes CDs one of the lowest-risk places to hold savings, though funds are generally locked in until maturity.
What is an early withdrawal penalty on a CD?
Most CDs charge a penalty for withdrawing before the maturity date — commonly a forfeiture of a set number of days' or months' interest, such as 90 days' interest on a 1-year CD. Withdrawing very early can make the penalty exceed the interest earned so far, meaning you could get back slightly less than your original principal. Always confirm a CD's exact terms before opening it.
How does compounding frequency affect my APY?
For the same stated APR, more frequent compounding produces a higher APY: daily > monthly > quarterly > annual. A 5.00% APR compounds to a 5.00% APY when compounded annually, but to about 5.13% APY when compounded daily. The gains shrink as frequency increases — the daily-vs-monthly gap is much smaller than the annual-vs-monthly gap.
How do I convert an APY back into an APR?
Use APR = n × [(1 + APY)^(1/n) − 1], where n is the compounding frequency. This reverses the standard APY formula (APY = (1 + APR/n)^n − 1). The "APY to APR converter" mini tool above performs this instantly for any compounding frequency.
What's the difference between a CD and a regular savings account?
A CD locks your money in for a fixed term (3 months to 5 years is common) at a fixed rate, with a penalty for early withdrawal. A savings account gives continuous access to your money at a variable rate that can change anytime. CDs suit money you won't need until a known date; savings accounts suit emergency funds and money you may need on short notice.

Methodology & sources

ToolPico's CD & Savings Calculator is a free, independent tool. The calculation engine applies standard compound-interest mathematics directly: future value is FV = P × (1 + APR/n)^(n×t), and the resulting Annual Percentage Yield is APY = (1 + APR/n)^n − 1 — the same disclosure formula required of US banks under the Truth in Savings Act (Regulation DD). Savings growth with recurring contributions is computed period by period (an annuity-style loop), and inflation-adjusted "real" values divide the nominal future value by (1 + inflation)^t. Results are computed instantly client-side in your browser; no data is sent to a server, and no live bank rates are queried.

Basis: standard compound-interest mathematics; Truth in Savings Act / Regulation DD (APY disclosure requirement); FDIC deposit insurance rules ($250,000 per depositor, per bank, per ownership category). Last updated: July 27, 2026. Results are for informational purposes only and do not constitute tax, investment, or financial advice; rates and terms vary by bank — confirm exact figures with your financial institution before opening an account.

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