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CD Calculator

Certificate of Deposit — maturity value, rate comparison, early withdrawal analysis & ladder builder

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Enter Your CD Details
Input your principal, APY, term, and compounding frequency. Use chips for quick presets.
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Analyze Scenarios
Compare growth charts, benchmark against HYSA and T-Bills, and explore the rate × term matrix.
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Build a CD Ladder
Spread principal across staggered maturities for regular liquidity without sacrificing yield.
Solve For
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%
mo
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P$10,000 ×(1+ APY/n— )^ n×t— (1−tax)— = After-Tax—
$0.00
Matures in 12 Months
Enter values to calculate your CD return
Final Value
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Interest Earned
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After-Tax Value
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Real Return
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Effective APR
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Tax Cost
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PeriodBalancePeriod InterestCumulative InterestAfter-Tax Balance

Bear / Base / Bull Scenarios

Rate shifted ±0.75% from your current APY. All compared against HYSA at 4.5%.

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Base
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Rate × Term Sensitivity Matrix

After-tax final value for every combination. ■ Low   ■ Mid   ■ High — current cell highlighted.

Rate Lock Value

Is it better to lock in your CD rate or stay in a floating HYSA?

Calculate on the Calculator tab first.

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Number of Rungs

Rates auto-adjust +0.1% per rung (longer terms typically earn more). Requires principal and APY from the Calculator tab.

Blended Annual Yield
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Total Interest
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Next Maturity
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Liquidity
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RungTermPrincipalRate Maturity DateInterestFinal Value

Ladder vs Alternatives

StrategyTotal InterestBlended RateLiquidityLock-In Risk

How to Use This Calculator

1
Enter your CD details — Set your principal, APY, term length, and compounding frequency. Use the quick-select chips for common term presets.
2
Switch solve modes — The calculator has four modes: solve for final value, required APY, required principal, or required term. Flip to any mode using the solve-for selector.
3
Compare scenarios — Open the Rate Comparison tab to benchmark your CD against a HYSA, T-Bills, and the market. The rate×term matrix shows how small APY differences compound over time.
4
Analyze early withdrawal — Use the Early Withdrawal tab to see exactly how much interest you'd forfeit at any month, including break-even points for reinvesting at a higher rate.
5
Build a CD ladder — The Ladder tab splits your principal across 2–5 CDs with staggered maturities, giving you regular access to funds without sacrificing yield.

Formulas & Methodology

Future Value (Compound)
FV = P × (1 + APY/n)n×t
P = principal, APY = annual rate, n = compounding periods/year, t = years
APY from APR
APY = (1 + APR/n)n − 1
Converts a nominal rate (APR) to effective annual yield (APY) for any compounding frequency
Early Withdrawal Penalty
EWP = P × (APY/365) × penalty_days
Most banks charge 3–12 months of interest as a penalty. Calculation uses simple interest on the forfeited period.
Real Return
Real Return = ((1 + APY) / (1 + inflation)) − 1
Measures actual purchasing power growth after inflation. A CD with 5% APY during 3% inflation yields a ~1.94% real return.

What Is a Certificate of Deposit?

A Certificate of Deposit (CD) is a time-deposit savings product offered by banks and credit unions. You deposit a fixed amount of money for a set term — anywhere from 1 month to 5 years — and the bank pays you a fixed interest rate in return. At maturity, you receive your principal plus all accrued interest.

CDs are FDIC-insured up to $250,000 per depositor per bank, making them one of the safest fixed-income instruments available. Unlike a savings account, you agree not to withdraw funds before the maturity date; doing so typically triggers an early withdrawal penalty.

CD vs. HYSA vs. T-Bills

High-yield savings accounts (HYSAs) offer similar safety but with variable rates — your APY can drop at any time. CDs lock in a rate, which is advantageous when rates are high and expected to fall. T-Bills are short-term US Treasury debt with competitive yields, no state income tax, and near-zero credit risk, but require purchasing in $100 increments through TreasuryDirect or a brokerage.

The CD Ladder Strategy

Instead of locking all your money in a single long-term CD, a CD ladder splits principal across multiple CDs with different maturities (e.g., 3-month, 6-month, 1-year, 2-year). As each shorter CD matures, you reinvest at the prevailing rate. This provides both regular liquidity and exposure to long-term rates without full commitment to a single term.

When CDs Make Sense

Key Terms

APYAnnual Percentage Yield — the effective annual return including compounding.
APRAnnual Percentage Rate — the nominal rate before compounding is applied.
EWPEarly Withdrawal Penalty — interest forfeited when breaking a CD before maturity.
CD LadderA strategy splitting principal across multiple CDs with staggered maturities.
Real ReturnReturn after subtracting inflation — measures actual purchasing power growth.
FDICFederal Deposit Insurance Corporation — insures CDs up to $250K per bank.

Real-World Examples

Emergency Fund Parking
$20,000 at 5.0% APY for 12 months (monthly compounding, 22% tax) = $21,000 gross / $20,780 after-tax. Better than a savings account, but consider a no-penalty CD for flexibility.
5-Year Growth
$50,000 at 4.5% APY for 60 months (daily compounding, 24% tax) earns ~$13,000 gross interest. Always check whether a brokered CD or T-Bill offers a higher after-tax yield.
4-Rung Ladder
$40,000 split into 4 x $10,000 CDs maturing at 3, 6, 12, and 24 months. Every rung that matures can be reinvested at current rates, giving both liquidity and a blended competitive yield.

Frequently Asked Questions

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