Free calculator
CD calculator
Project maturity on a one-time deposit: enter principal, the quoted APY (annual percentage yield), your term in months or years, and how often you want to model compounding (default daily). We show total interest and ending balance when interest stays in the account—illustration only, not a bank offer or a live rate quote.
When to use this calculator
A fast what-if for U.S. certificate of deposit (CD) or similar term-deposit math—the same transparent FV line you can paste into a workbook.
- Compare a maturity total when you have APY and a concrete term, before you read the long prospectus or bank UI.
- Sanity-check marketing numbers ($10,000, 1 year, 4% APY) with one set of compounding and term assumptions (see FAQ for what banks may do differently).
- Copy the Sheets/Excel cells after you align APY (decimal), compounding count, and years with the cards below—keep currencies consistent.
We use a lump-sum only (no contributions mid-term) and reinvested interest so the balance can compound on the same schedule you pick. APY is the headline annual number many banks show for a product class.
Map APY to a nominal annual r
We match (1 + r / n)ⁿ = 1 + APY in decimal (for one year) so a 1-year run lines up with the stated APY when the n-per-year compounding is applied. Then we roll forward n · t periods: FV = P (1 + r / n)ⁿᵗ (same as A = P (1 + r/n)ⁿᵗ in finance texts).
Compounding frequency is yours to set
Banks may use 365-day or other accrual rules. We use n = 12 / 4 / 2 / 1 / 365 as you select so you can line up a prospectus or disclosure—your n and t are still yours to calibrate to the source.
Not modeled on purpose
Early withdrawal penalties, income tax, inflation, call features, and interest paid out to another account (no in-CD compounding) are not in v1. Brokered and bump CDs are not priced here. For long savings paths with monthly deposits, the compound interest calculator is the better PDP.
We do not fetch live market APYs; enter what you see in a table or from your bank. For U.S. CD and FDIC/NCUA education, use official and consumer-finance sources—treat this page as pencil math only.
Google Sheets & Excel
Two steps: first match the stated APY to a nominal annual r for your compounding count, then compound a lump sum to maturity. B2 = APY as a decimal (0.04 = 4%), C2 = compounding periods per year (e.g. 365), D2 = term in years—details on each card.
=C2*(POWER(1+B2,1/C2)-1)Place the formula in E2 (or another cell and point the next formula to it). B2 = APY as a decimal (0.04 = 4%); C2 = compounding periods per year (12 = monthly, 365 = daily). Same POWER spelling in US Excel and Google Sheets.
=A2*POWER(1+E2/C2,C2*D2)A2 = principal. E2 = nominal annual r from the first card. C2 = periods per year; D2 = full term in years (e.g. 18 months → 1.5). For semiannual compounding use C2=2; quarterly 4; monthly 12; daily 365; annual 1.
Frequently asked questions
What does this CD calculator do?
It estimates maturity value and total interest from principal, stated APY, term (in months or years), and a compounding schedule for in-account accrual. It is illustration only.
What is APY on a CD?
APY (annual percentage yield) is a one-year way to quote how much a savings product can grow, including compounding the way a bank or credit union describes it. It is not the same as a simple stated rate unless compounding and disclosure say so—see the methodology above.
APY vs interest rate—what should I type?
Use the APY (%) field: we convert APY to a periodic r for your compounding count. If a site only shows a stated rate, check their APY (often a footnote) and enter APY here to avoid mixing definitions.
Why does the result change with daily vs monthly compounding?
With the same APY, a higher n (more compounding) usually gives a slightly higher ending balance; our APY mapping is built so a 1-year case still respects the stated APY when n matches the disclosure story you choose.
How do I model a 6- or 12-month CD?
In Whole months mode, enter 6 or 12; in Fractional years, use 0.5 or 1. The term in years feeds the same FV line in the methodology.
Is this for brokered CDs?
Not in v1. Brokered and step-up products can have market and accrual rules we do not implement—treat the tool as core bank-CD pencil math, then follow your broker’s or bank’s own numbers.
What if the bank pays interest to my checking each month?
That is payout mode: interest leaves the CD so it may not compound on the same balance. This page assumes reinvested in-CD accrual; your maturity could be lower with payouts.
What if I need money before maturity?
Most CDs have penalties; we do not calculate them. Use a bank or regulator’s disclosure for the forfeiture and time rules, or a dedicated penalty explainer for your term and institution.
Is my CD FDIC-insured?
Many U.S. bank CDs are covered when the bank is an FDIC-insured institution and you stay within limits—but eligibility and limits (e.g. $250,000 for depositor categories at one bank) are a separate question from the math here. Verify on fdic.gov and your statement.
How much interest is $10,000 at 4% APY for 1 year?
A $10,000 one-year case at 4% APY is very close to $400 interest and $10,400 maturity; compounding granularity and roundoff on this page can nudge the pennies. Enter 4, $10,000, 12 months, and the same n to mirror your use case.
When should I use the compound interest tool instead?
Use the compound interest calculator for contribution paths, other compounding or savings frequencies, and ending-balance exploration over a horizon—this CD view is a lump sum maturity lens with one APY and one term.
How do I line this up in Google Sheets or Excel?
Use the two copy cards. B2 must be APY as a decimal; A2 is your principal; C2 and D2 match the tool’s compounding and term in years. In non-English Excel, POWER may be POTENZ / PUISSANCE; ; is often the argument separator in de—use Formulas → Insert function to match your language pack.
Is this investment, tax, or banking advice?
No. The page is a free educational calculator and is not a recommendation to open, break, or replace a CD, and is not legal, tax, or compliance advice for you or your jurisdiction.