CD Calculator
Find out exactly what a certificate of deposit will be worth at maturity, before you lock your money in, using the calculator below.
Most CDs don't allow adding funds after you open them.
Use what your bank shows. Most banks advertise APY.
Only used to convert APR into an effective APY.
Common terms: 3, 6, 12, 18, 24, 36, 60 months.
This is a general estimate, not financial, investment, or tax advice.
Table of contents
How this calculator works
If you enter an APY (the most common way banks advertise CD rates), this calculator uses Maturity = Principal × (1 + APY)^(term in years) directly, since APY already accounts for compounding. That's why the compounding frequency field only appears when you select APR: if you only know the nominal rate, we convert it to an effective APY first using APY = (1 + APR/n)^n − 1, then apply the same maturity formula. Some calculators always ask for compounding frequency even when it can't change the answer — we only ask when it actually matters.
Worked example
A $5,000 deposit at 4.50% APY for a 12-month term grows to $5,225.00 at maturity — $225.00 in interest. This is the default example pre-filled above; adjust any field to see your own numbers. (Illustrative only, not a current live rate.)
Frequently asked questions
What's the difference between APY and APR on a CD?
APY (Annual Percentage Yield) already includes the effect of compounding. APR is the nominal annual rate before compounding is applied. Most banks advertise CDs using APY, since it's the more accurate picture of what you'll actually earn.
If I already know my APY, does compounding frequency matter?
No. APY already incorporates whatever compounding frequency your bank uses, so once you have it, entering a separate compounding frequency wouldn't change your maturity value. It only matters if you're converting from an APR.
What happens if I withdraw from a CD before it matures?
Most CDs charge an early withdrawal penalty, often calculated as a set number of months of interest depending on the term length. In some cases the penalty can reduce your principal, not just the interest you would have earned. See High-Yield Savings vs. CDs for more on this trade-off.
Is CD interest taxable?
Generally yes. CD interest is typically taxed as ordinary income at the federal level (and in most states) in the year it's credited to your account. This calculator shows pre-tax estimates only.
What are typical CD terms?
Common CD terms are 3, 6, 12, 18, 24, 36, and 60 months, though some banks offer other lengths, sometimes to feature a promotional rate.
Sources
- Early withdrawal penalties and how they're calculated — CNBC Select
- CD interest is generally taxed as ordinary income — Firstcard
- Common CD terms — CD Calculator Pro
How This Calculator Is Verified
Built by Cedrick Reese. Every formula on this page is checked against multiple independent sources before publishing, and cross-verified against real calculations before this page went live -- not just written once and trusted.
Last reviewed: August 25, 2026