CD Calculator

CDs quote an APY (annual percentage yield), which already includes compounding — so the value at maturity is deposit × (1 + APY)^(months ÷ 12). A $10,000 CD at 4.00% APY held for 12 months is 10,000 × 1.04 = $10,400.00, which is exactly $400 of interest. Part-years are pro-rated in the exponent: the same CD over 18 months (1.5 years) grows to 10,000 × 1.04^1.5 = $10,605.96, and over 36 months to $11,248.64. Whether your bank compounds daily or monthly changes when interest posts, not the total — the APY convention bakes the compounding in. The 4.00% used here is an illustrative rate, not a live quote.

They solve different problems. A CD locks in a fixed APY for a fixed term, so the rate can't fall on you — but your money is locked too, and getting it out early costs a penalty of typically 3–12 months of interest. A savings account keeps the money available any time, but its rate is variable and can drop without notice. The usual split: emergency funds and money you might need on short notice belong in savings; money with a known future date — a down payment in two years, tuition next fall — suits a CD, because you're paid to commit. CDs also don't accept additional deposits, so ongoing monthly saving belongs in a savings account.

Your bank gives you a short grace period — often around 7 to 10 days, but check your account disclosure — during which you can withdraw the money penalty-free, add funds, or move to a different term. If you do nothing, most CDs auto-renew into a new CD of the same term at the bank's current rate, which may be lower than the rate you had, and the early-withdrawal penalty clock restarts. Put the maturity date in your calendar and decide before the grace window closes — auto-renewal at a weak rate is the most common way CD savers leave money on the table.

Banks typically charge 3 to 12 months of interest, taken from the CD's balance when you cash out early. This calculator models the penalty as the interest your deposit would earn over the penalty months. Worked example: a $10,000 CD at 4.00% APY with a 6-month penalty, broken at month 6 — the balance is $10,198.04 ($198.04 accrued), the penalty is six months of interest, $198.04, so you walk away with exactly $10,000.00: your principal back, all earnings wiped. Break the same CD at month 3 and only $98.53 has accrued but the penalty is still $198.04, so the net is $9,900.50 — the penalty dips into your principal. Always check the penalty terms in your CD's disclosure before you buy.

Yes — CDs at FDIC-insured banks are deposits, covered up to $250,000 per depositor, per insured bank, per ownership category (fdic.gov). A joint CD with two owners is insured up to $500,000 — $250,000 per co-owner. Credit-union CDs, called share certificates, carry the same $250,000 coverage through the NCUA. If you have more than the limit to place, spread it across separately insured banks or different ownership categories — insurance is per bank, not per CD, so ten CDs at one bank still share one $250,000 cap.

A CD ladder splits a lump sum across CDs with staggered maturities so a portion comes due at regular intervals. The classic build: $50,000 split into five $10,000 CDs maturing in 1, 2, 3, 4 and 5 years. At an illustrative flat 4.00% APY the rungs mature at $10,400.00, $10,816.00, $11,248.64, $11,698.59 and $12,166.53 — $56,329.76 in total, $6,329.76 of interest. The payoffs: a rung matures every year, so you're never more than a year from penalty-free access to part of the money; and as each rung matures you roll it into a new 5-year CD, so after the ramp-up every dollar earns the long-term rate while keeping annual liquidity. In real markets, longer terms usually carry different rates than short ones — this calculator applies your single illustrative APY to every rung to keep the mechanics clear.

CD interest is taxable as ordinary income in the year it's credited to your account — even if you don't withdraw a cent until maturity. Your bank reports it to you and the IRS on Form 1099-INT. There's no capital-gains treatment for CD interest. One exception: CDs held inside an IRA follow the IRA's rules instead — tax deferred in a traditional IRA, tax-free in a Roth subject to its withdrawal rules.

A brokered CD is issued by a bank but bought through a brokerage account. Two practical differences: instead of paying an early-withdrawal penalty, you exit by selling the CD on the secondary market — where the price can be above or below what you paid, especially if rates have moved; and some brokered CDs are callable, meaning the bank can end them early when rates fall. FDIC insurance passes through to you as long as the issuing bank is FDIC-insured and the CD is properly titled, still counting toward your $250,000 per-bank limit. Brokered CDs suit people managing several banks' worth of deposits from one account; bank CDs are simpler for a single deposit.

Generally no — a standard CD takes one deposit at opening and locks it until maturity; that certainty is what the fixed rate is paying for. (A small minority of 'add-on' CDs allow extra deposits, but they're uncommon and usually pay less.) If you want to save a monthly amount and watch it compound, that's a different tool: use our Compound Interest Calculator for regular contributions at a steady rate, or the Savings Goal Calculator to work out the monthly deposit a target needs.