CD Calculator – See Exactly How Much Your Deposit Will Earn

This CD calculator takes three inputs — your deposit amount, interest rate, and term length — and shows you exactly what you'll walk away with at maturity. Whether you're comparing rates from different banks, trying to decide between a 6-month and a 2-year CD, or simply want to know if locking up your savings is worth it, this tool gives you a clear answer in seconds.

Enter your numbers, choose months or years, and you'll see your total balance and the exact interest you'll earn — along with a chart showing how your money grows over time.

A certificate of deposit is a savings product offered by banks and credit unions where you deposit a fixed amount of money for a set period of time — called the term — and earn a guaranteed interest rate in return.

Unlike a regular savings account, you agree not to touch the money until the CD matures. In exchange for that commitment, banks typically offer higher interest rates than they would on standard savings accounts.

CDs are considered one of the safest savings options available because they're FDIC-insured up to $250,000 per depositor at member banks. Your principal is protected, and your return is locked in from day one.

The core tradeoff: Higher guaranteed returns in exchange for restricted access to your funds.

CDs earn compound interest, which means the interest you earn also starts earning interest over time. This is what separates compound growth from simple interest — and it's why longer-term CDs tend to perform noticeably better than their rate alone might suggest.

For monthly compounding (when you enter your term in months):

A = P × (1 + r/12)^t

Where A is the final balance, P is your principal deposit, r is the annual interest rate as a decimal, and t is the term in months.

For annual compounding (when you enter your term in years):

A = P × (1 + r)^t

Where t is the number of years.

What this means in practice: A $10,000 deposit at 10% for 6 months returns $488.09 in interest — not the flat $500 you'd get from simple interest. The difference comes from compounding: each month's interest becomes part of the balance that earns next month's interest.

Using the calculator takes about 30 seconds:

1. Enter your deposit amount — Type in how much you plan to put into the CD. This is your starting principal. There's no minimum required by the calculator, so you can test any amount.
2. Enter the interest rate — Input the annual interest rate your bank is offering. You'll find this on the bank's website or account offer. Note: some banks advertise APY (Annual Percentage Yield) instead of a flat rate — if that's the case, enter the APY value here for the closest estimate.
3. Enter the term length — How long will your CD run? Toggle between Months and Years depending on how the bank describes the term. A 6-month CD? Click Months and enter 6. A 2-year CD? Click Years and enter 2.
4. Read your results — The calculator instantly shows your total balance (what you'll receive at maturity) and total interest earned (your profit). The bar chart below the results lets you see how both figures grow over each period within your term.

Change any value and the results update immediately.

Here's what different CD scenarios actually look like:

You have $5,000 sitting in a checking account earning almost nothing. You find a 6-month CD at 5% and decide to move it.

• Deposit: $5,000
• Rate: 5%
• Term: 6 months
• Interest earned: ~$123
• Total balance: ~$5,123

Not a windfall — but it's money you were leaving on the table anyway, and your principal is fully protected.

Rates look like they're heading down. You have $20,000 and want to lock in 5.25% for a full year before that window closes.

• Deposit: $20,000
• Rate: 5.25%
• Term: 1 year
• Interest earned: ~$1,050
• Total balance: ~$21,050

One year, one decision, over a thousand dollars in guaranteed interest.

You're saving for a goal 3 years out and want something safe. You put $15,000 into a CD at 4.5% for 3 years.

• Deposit: $15,000
• Rate: 4.5%
• Term: 3 years
• Interest earned: ~$2,096
• Total balance: ~$17,096

The compounding effect does real work here — each year's interest feeds into the next year's base.

Not sure if a CD is right for you? Run the numbers on $1,000 at 4% for 12 months.

• Interest earned: ~$40
• Total balance: ~$1,040

The return is modest, but the principle is clear: even small deposits benefit from locking in a rate rather than leaving money idle.

The term toggle matters more than it might seem — here's how to think about it:

Short-term CDs (3–12 months) make sense when:

• You expect to need the money within the year
• You believe interest rates will rise and want to re-invest soon
• You're parking cash between larger financial decisions

Long-term CDs (1–5 years) make sense when:

• You have a specific future goal (home purchase, education, retirement supplement)
• Current rates are high and you want to lock them in
• You want guaranteed returns without monitoring the market

One useful strategy: CD laddering — splitting a lump sum across multiple CDs with staggered maturity dates. For example, putting equal amounts into 6-month, 1-year, 2-year, and 3-year CDs gives you regular access to a portion of your savings while still benefiting from higher long-term rates on the rest. Use the calculator to model each rung separately and compare total returns side by side.

Shop aggressively. Rates vary significantly between institutions. Online banks and credit unions frequently offer 0.5% to 1% higher APYs than traditional brick-and-mortar banks on identical terms. Use this calculator to translate that rate difference into actual dollars — the gap is often surprising.

Watch the early withdrawal penalty. Most CDs charge a penalty if you withdraw before maturity — typically 60 to 180 days of interest, depending on the term. Factor this in before committing to a longer term, especially if there's any chance you'll need the funds early.

Check whether interest compounds or pays out. Some CDs reinvest interest back into the account (compounding); others send periodic interest payments to a linked account. This calculator assumes compounding. If your CD pays out interest monthly, your maturity balance will be slightly lower.

Time your CD with your goals. A CD that matures right when you need the money is a planning win. Use the term selector to align your CD's maturity date with a specific milestone.

Consider taxes. CD interest is taxable in the year it's earned or credited, even if you don't withdraw it. Factor your marginal tax rate into the net return calculation, particularly on larger deposits or longer terms.

This calculator uses compound interest — widely considered the standard for CD calculations — with monthly compounding applied when you enter a term in months, and annual compounding when you enter a term in years. Results are rounded to the nearest cent.

CD earnings shown are pre-tax gross returns. Your actual after-tax return will depend on your individual tax situation. For large deposits or complex scenarios, consider consulting a financial advisor.