Free calculator · USD

CD Calculator

See what a fixed-rate certificate of deposit could earn. Start with an APY, or switch to a nominal interest rate.

Maturity value before tax(Example)

$10,500.00

Full result

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Which rate do you have?

Common terms

Include a simplified tax estimate

Maturity value before tax

$10,500.00

Example · not a bank offer

Total interest: $500.00
Equivalent APY: 5%

A fixed-rate estimate with interest left in the CD. Actual day counts, crediting dates, early withdrawals, and fees can change your payout.

Your amounts stay in browser memory. No account, bank connection, or upload is needed. Use Clear all to reset them. An optional APY-to-CD rate transfer is used once and expires after one minute; reloads do not restore it. Downloaded CSV files remain on your device.

Monthly accrual schedule (12)

Estimated accrued balances, not actual monthly payments. Whole-month periods use an equivalent-growth model. Displayed monthly interest is the change between rounded cumulative balances so the rows reconcile.

Estimated accrued balances, not actual monthly payments. Whole-month periods use an equivalent-growth model. Displayed monthly interest is the change between rounded cumulative balances so the rows reconcile.
Month	Interest (USD)	Total interest (USD)	Accrued balance (USD)
1	$40.74	$40.74	$10,040.74
2	$40.91	$81.65	$10,081.65
3	$41.07	$122.72	$10,122.72
4	$41.24	$163.96	$10,163.96
5	$41.41	$205.37	$10,205.37
6	$41.58	$246.95	$10,246.95
7	$41.75	$288.70	$10,288.70
8	$41.92	$330.62	$10,330.62
9	$42.08	$372.70	$10,372.70
10	$42.26	$414.96	$10,414.96
11	$42.44	$457.40	$10,457.40
12	$42.60	$500.00	$10,500.00

Calculate my net worth

How the CD estimate works

The calculator models a fixed-rate CD with interest reinvested until maturity. It estimates growth, not a bank-specific payment schedule or tax return.

APY and nominal interest are different inputs

APY: balance = principal × (1 + APY)^(months / 12)

Enter percentages in the form; the formula uses decimals. With $10,000 at 5% APY for 12 months, the estimated balance is $10,500 and interest is $500. APY includes compounding, so it must not be compounded a second time.

CFPB: interest rate and APY definitions

Using a nominal annual rate

Nominal: balance = principal × (1 + rate / n)^(n × months / 12)

Here n is the number of compounding periods per year. A 5% nominal rate compounded monthly is about 5.1162% APY. Fractional compounding periods use equivalent growth; real banks may apply different day counts and crediting rules. This is not a loan APR converter.

A transparent, simplified tax estimate

After-tax interest = interest × (1 − assumed tax rate)

At a 24% assumed tax rate, $500 interest leaves $380 after an estimated $120 tax. The model treats tax as paid outside the CD and keeps the before-tax compounding path unchanged. Interest can be taxable each year; account type, state taxes, deductions, and timing are not modeled.

IRS: interest income and tax timing

Check the actual deposit terms

Early withdrawal penalties and special CD features can change returns. FDIC coverage is generally $250,000 per depositor, per insured bank, per ownership category; not a separate limit for every CD. Confirm the bank, coverage, and product agreement before opening an account.

FDIC: deposit insurance coverage

Common questions

Does this show current bank rates?

No. Enter the APY or nominal rate from the offer you are considering. The 5% starting value is a calculation example, not a current offer or recommendation.

Can I add money or withdraw early?

This model assumes one initial deposit and no early withdrawals or fees. Add-on, variable-rate, brokered, and callable CDs may need a different model. Use the actual product agreement to assess those terms.

Why can the monthly table differ from a bank statement?

The table estimates accrued growth over equal month fractions. A bank may use exact dates, a different day-count basis, periodic interest payments, or different rounding. The final estimate is useful for comparison, not a promised payout.