Certificate of deposit ladder planner
CD Ladder Calculator
Split one deposit into equal CD rungs, enter an APY for each term, and estimate each first and renewed maturity. Rates are scenarios, not live bank quotes.
CD ladder results
Timing note: totals add proceeds received on different maturity dates. They are not a portfolio value measured on one common date.
| Rung | Initial principal | First maturity | APY | First proceeds | First interest | Renewal term | Renewal APY | Renewed maturity | Renewed proceeds |
|---|
How the CD ladder calculation works
The calculator divides the total deposit equally among the selected number of rungs. Each rung receives a different term and the APY you enter for that term. When a rung reaches its first maturity, the model reinvests all of its proceeds for the ladder’s longest term at the assumed renewal APY.
Initial allocation per rung: A = total deposit ÷ number of rungs.
First maturity: Mi = A × (1 + APYi)monthsi ÷ 12.
Renewed maturity: Ri = Mi × (1 + renewal APY)longest term ÷ 12.
APY is already an effective annual yield, so the formula does not add a separate compounding-frequency assumption. Partial-year terms use a fractional exponent. Bank day-count rules and posting dates may differ slightly.
Verified five-rung example
A $25,000 ladder split equally across 12-, 24-, 36-, 48-, and 60-month CDs places $5,000 in each rung. At APYs of 4.00%, 4.10%, 4.20%, 4.30%, and 4.40%, the first maturity proceeds are $5,200.00, $5,418.41, $5,656.83, $5,917.08, and $6,201.15. Their sum is $28,393.47, including $3,393.47 of interest received on different dates.
If every first maturity is reinvested for 60 months at 4.50% APY, the renewed proceeds sum to $35,383.42 when those second maturities occur from month 72 through month 120. This is a scenario, not a promise that the same renewal rate will be available.
Why build a CD ladder?
- Staggering maturities can create recurring access to part of the deposit instead of locking the entire amount until one date.
- Reinvesting matured rungs into the longest selected term can maintain a regular maturity cadence after the ladder is established.
- Separate APYs let you model the current rate for each term rather than assuming a flat yield curve.
Limits and assumptions
This calculator assumes equal initial allocations, fixed APY within each CD, no withdrawals before maturity, and full reinvestment at one assumed renewal APY. It excludes taxes, early-withdrawal penalties, fees, changing renewal rates, callable or market-linked CDs, brokered-CD price changes, accrued-interest conventions, weekends, holidays, and deposit-insurance limits. Confirm issuer terms and coverage; results are estimates, not financial advice.
Related calculators
- CD Calculator — estimate one CD, including an optional early-withdrawal penalty.
- APY Calculator — convert APR and APY or derive annual yield from balances.
- Compound Interest Calculator — model recurring contributions and longer-term growth.
- Bond Price Calculator — calculate bond price, yield, current yield, and duration.