CD Interest Calculator
Enter your deposit, the CD's APY, and the term. You'll get the value at maturity, the interest earned, and the same deposit compared across other terms.
CDs are usually a single deposit, locked until maturity
The quoted APY already includes compounding
Value at maturity
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Enter a deposit
Interest earned
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Effective monthly earning
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The trade: liquidity for a locked rate
A certificate of deposit is a simple bargain: you give up access to the money for a fixed term, and the bank gives up the right to change your rate. That second half is the point. Savings rates float with the market and can fall the month after you open the account; a CD's APY is written into the contract on day one. The calculator's "interest earned" number isn't a projection, it's a promise, which is rare in personal finance. The price of that certainty is that the money is spoken for until maturity.
Penalties, in plain words
Break the lockup and the bank claws back interest: commonly around 3 months' worth on shorter CDs and 6 to 12 months' worth on longer ones. Two things follow from that. First, never put emergency money in a CD; the emergency fund belongs somewhere you can reach it at 2am. Second, match the term to a real date. A CD maturing two months after the tuition bill or the house closing is a penalty waiting to happen, and the fix is simply choosing the shorter term up front.
Ladders, and when savings wins
A CD ladder splits the deposit across staggered terms so a piece matures every year: you collect long-term rates on most of the money while regaining access on a schedule, and each maturing rung rolls into a new long CD at whatever rates are then. It's a fine structure for cash you won't need on a surprise basis. But when the timeline is fuzzy, the high-yield savings account usually wins on flexibility alone, a comparison our HYSA guide walks through. Either way, cash earning a real rate is an asset worth watching next to everything else, which is exactly the one-screen view Stoia keeps current for you.
Frequently asked questions
How is CD interest calculated?
Banks quote CDs in APY, which already includes compounding, so the math is one line: value at maturity = deposit times (1 + APY) raised to the term in years. A $10,000 CD at 4% APY ends a 12-month term at $10,400; the same rate over 6 months ends near $10,198 because the exponent is half a year.
What happens if I cash out a CD early?
Most CDs charge an early withdrawal penalty, typically several months of interest (often 3 months' worth on short terms, up to a year or more on 5-year CDs). The penalty comes out of earned interest first, but on a young CD it can cut into your principal. No-penalty CDs exist and pay a slightly lower rate in exchange for the exit door.
Is a CD better than a high-yield savings account?
They solve different problems. A CD locks a rate for money you won't touch before a known date; a high-yield savings account keeps money reachable but its rate can drop any month. For an emergency fund, liquidity wins and savings is the better home. For a down payment due in 18 months, a CD's locked rate can be worth the lockup.
What is a CD ladder?
Splitting one deposit across several terms, say equal pieces in 1, 2, 3, 4, and 5-year CDs, so something matures every year. Most of the money earns long-term rates while a chunk becomes liquid on a schedule, and each maturing CD can roll into a new long one.
Do I pay taxes on CD interest?
Yes. CD interest is ordinary income in the year it's credited, even if you leave it in the CD until maturity, and the bank reports it once you earn $10 or more. Inside an IRA the usual retirement account rules apply instead.
Does this calculator save my numbers?
No. Everything runs in your browser and disappears when you leave. Nothing is uploaded or stored.
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