CD / Money Market Calculator
Two deposit products, one calculator. The arithmetic underneath is identical, so what changes between the tabs is the product rules: a fixed term and a penalty on one side, access and ongoing deposits on the other.
A CD locks a single deposit away for a fixed term. Taking the money out early means paying a penalty to the bank.
Your maturity value will appear here
Pick a CD or a money market account, enter your deposit, rate and term, then calculate.
Why this is separate from our savings tools
CD/Money Market vs. our Savings Calculator: a savings account tool assumes a variable rate and free withdrawals. This page adds the things that only apply to deposit products: a fixed term in months with a maturity date, the penalty for pulling out early, a tax switch and a yield-to-term column.
Against our Compound Interest Calculator: that one is the general-purpose engine. This page is the product-specific version, using CD and money market language and current market rates as a reference point.
Also see the APR / APY Calculator: that one converts percentages between forms, while this one calculates dollar amounts for a specific deposit product.
Quick Answer
A CD or money market balance grows at APY = 100 x [(1 + i/n)^n - 1], where i is the nominal annual rate and n is the compounding periods per year. $10,000 in a five-year CD at 4.0% compounded monthly matures at $12,209.97, an APY of 4.074%. On a CD, the early withdrawal penalty usually matters more to the comparison than the compounding frequency does.
How It Works: Formula & Variables
The yield calculation
APY = 100 × [(1 + i/n)n − 1]
- i
- The nominal annual interest rate the bank quotes.
- n
- Compounding periods per year.
Turning that into money: Interest = Principal × (APY/100). Neither of the two main consumer calculators for these products publishes an explicit compounding formula, so we use the statutory APY definition from the Truth in Savings rules as the engine here.
What the two products actually are
A certificate of deposit, or CD, is “a type of savings account offered by banks and credit unions”, with a fixed term meaning “the time you agree to leave your money in the CD”. Break that early and “withdrawing money early means paying a penalty fee to the bank”.
A money market account is “a type of account offered by banks and credit unions... insured by the FDIC or NCUA, up to $250,000 held by the same owner or owners”. The money stays reachable, which is the whole point of choosing one over a CD.
The tax switch
Interest on both products is normally taxable, and how you settle that bill changes the outcome. Paying the tax out of the interest as it is earned removes that money from the account, so it earns nothing further. Paying from elsewhere leaves the whole interest amount compounding. The calculator handles both.
What rates look like right now
Useful as a sanity check on whatever your bank is offering.
| Product | Rate | As of |
|---|---|---|
| National average savings account | 0.38% | July 2026 (FRED SNDR) |
| Money market, under $100k | 0.61% | June 2026 (FRED MMNDR) |
| 12-month CD, under $100k | 1.68% | July 2026 (FRED NDR12MCD) |
| Average 1-year CD | 2.01% APY | 26 July 2026 (Bankrate) |
| Average 3-year CD | 1.68% APY | 26 July 2026 (Bankrate) |
| Average 5-year CD | 1.73% APY | 26 July 2026 (Bankrate) |
| Highest available 6-month CD | 4.10% APY | 4 June 2026 (Bankrate) |
| Highest available 1-year CD | 4.11% APY | 4 June 2026 (Bankrate) |
| Highest available 3-year CD | 4.15% APY | 4 June 2026 (Bankrate) |
| Highest available 5-year CD | 4.20% APY | 4 June 2026 (Bankrate) |
Shopping beats optimising. The distance between the national average and the best rates on the board is far bigger than the distance between compounding frequencies. Moving from a 1.68% average one-year CD to a 4.11% one is worth roughly two and a half points. Switching that same CD from annual to daily compounding is worth a few hundredths.
Worked Examples
Example 1: $20,000 in a 60-month CD at 5.5%
A single deposit, left alone for five years, with the yield to term shown at each anniversary.
| Year | Opening | Closing | Yield to term |
|---|---|---|---|
| 1 | $20,000.00 | $21,128.16 | 5.641% |
| 2 | $21,128.16 | $22,319.95 | 11.600% |
| 3 | $22,319.95 | $23,578.97 | 17.895% |
| 4 | $23,578.97 | $24,909.01 | 24.545% |
| 5 | $24,909.01 | $26,314.08 | 31.570% |
Example 2: $10,000 in a five-year CD at 4.0%, compounded monthly
With n = 12, the balance after 60 months is 10,000 × (1 + 0.04/12)60 = $12,209.97.
The matching yield is APY = (1 + 0.04/12)12 − 1 = 4.074%. That is the number to compare against another bank's offer, because it already has the monthly compounding baked in.
Key Concepts
The term is the trade: a CD pays more than an equivalent money market account because you give up access. Price that access rather than treating the extra yield as free.
The penalty is part of the rate: a 5-year CD you might break in year two is not really a 5-year CD. Run the penalty figure before deciding the term is worth it.
Both are insured: FDIC or NCUA coverage runs to $250,000 per owner or set of owners, so the choice between them is about access and yield, not safety.
Yield to term is cumulative, APY is annual: the yield-to-term column shows total growth since day one, so it climbs past the APY as the years stack up. They are not two versions of the same number.
Common Mistakes
Comparing CDs without pricing the early withdrawal penalty: two offers at the same APY are not equivalent if one charges three months of interest to break and the other charges twelve.
Treating a money market account as being as fixed as a CD: money market rates are variable and can move under you. A CD rate is locked for the term, which cuts both ways.
Taking the national average as the going rate: the average 12-month CD sat at 1.68% in July 2026 while the best available paid 4.11%. Shopping around is the single biggest lever here.
Frequently Asked Questions
A certificate of deposit, or CD, is a type of savings account offered by banks and credit unions. You agree to leave the money in place for a fixed term, and withdrawing money early means paying a penalty fee to the bank.
Yes. A money market account is a type of account offered by banks and credit unions, insured by the FDIC or NCUA, up to $250,000 held by the same owner or owners.
A CD asks you to commit to a fixed term and charges a penalty if you break it early. A money market account leaves your money reachable while it earns interest, and you can keep paying into it.
The national average on a 12-month CD was 1.68% in July 2026. The best available one-year CD was paying 4.11% APY as of 4 June 2026. The gap between the average and the top of the market is worth more than any amount of tinkering with compounding frequency.
The calculator lets you choose between paying the tax out of the interest as you go, which stops that money earning anything further, and reinvesting the full interest and settling the tax from elsewhere. Actual rates depend entirely on your own situation, so treat the percentage you enter as your own estimate.
Yes, and that is a real difference between the two products. Monthly deposits are a normal input for a money market account. A CD works from a single deposit plus a term.
Related Calculators
Savings Calculator
Project a savings balance from a starting amount, monthly deposits and your bank APY.
Compound Interest Calculator
The general-purpose compounding tool, with annual through continuous frequencies.
APR / APY Calculator
Convert a nominal rate into an effective APY, or into a cost-inclusive APR.
Savings Goal Calculator
The monthly deposit needed to hit a savings target by a set date.
Future Value Calculator
Project a lump sum plus optional contributions at any rate and frequency.
Inflation Calculator
Check what your maturity value will actually be worth in purchasing power.
Sources
- 12 CFR Part 1030, Appendix A (Truth in Savings, Regulation DD; the APY formula used as the engine here): https://www.ecfr.gov/current/title-12/chapter-X/part-1030/appendix-Appendix A to Part 1030
- TheCalculatorSite, APY Calculator (Interest = Principal x (APY/100), and money market deposits as an input): https://www.thecalculatorsite.com/finance/calculators/apy-calculator.php
- Consumer Financial Protection Bureau, what is a certificate of deposit: https://www.consumerfinance.gov/ask-cfpb/what-is-a-certificate-of-deposit-cd-en-917/
- Consumer Financial Protection Bureau, what is a money market account: https://www.consumerfinance.gov/ask-cfpb/what-is-a-money-market-account-en-915/
- CalculatorSoup, CD Calculator (the $20,000 five-year schedule and the tax handling options): https://www.calculatorsoup.com/calculators/financial/cd-calculator.php
- FRED, national savings deposit rate (SNDR): https://fred.stlouisfed.org/series/SNDR
- FRED, money market deposit rate under $100k (MMNDR): https://fred.stlouisfed.org/series/MMNDR
- FRED, 12-month CD rate under $100k (NDR12MCD): https://fred.stlouisfed.org/series/NDR12MCD
- Bankrate, current CD interest rates (average and highest available APYs): https://www.bankrate.com/banking/cds/current-cd-interest-rates/