The 60-second rule
Locked yield beats the ladder when rates stand still; the ladder wins when they move against you. On $50,000, the five-rung ladder (4.75 / 4.75 / 4.85 / 4.55 / 5.00%) finishes at $63,450.98 pre-tax — $60,491.76 after 22% federal tax. The single 5-year CD at 5.00% finishes at $63,814.08 pre-tax — $60,774.98 after tax. The single CD wins by $283.22. Rolling 1-year CDs at 4.75% trails at $60,185.24 after tax. Default check: $60,774.98 − $60,491.76 = $283.22 to the single CD. The ladder’s prize is not the total — it’s liquidity: a rung matures every year, so some money becomes reachable without breaking anything.
The worked example, line by line
Setup: $50,000, five $10,000 rungs at 4.75 / 4.75 / 4.85 / 4.55 / 5.00%, 22% federal tax, 0% state tax, rates flat.
Line 1 — the rungs mature. 1-year: $10,000 × 1.0475 = $10,475.00 · 2-year: $10,000 × 1.04752 = $10,972.56 · 3-year: $10,000 × 1.04853 = $11,526.71 · 4-year: $10,000 × 1.04554 = $11,948.03 · 5-year: $10,000 × 1.055 = $12,762.82.
Line 2 — maturing rungs reinvest. Each of the first four rungs rolls into a new 5-year CD at 5.00% for its remaining years: $12,732.43, $12,702.11, $12,708.20, $12,545.43. Ladder total: $63,450.98 — $13,450.98 of interest.
Line 3 — the single CD. $50,000 × 1.055 = $63,814.08 — $13,814.08 of interest. Every dollar earns the highest rung rate; the ladder’s lower rungs (4.55–4.85%) drag its blend down.
Line 4 — after tax. Keep 78% of the interest: ladder $60,491.76 · single CD $60,774.98 · rolled 1-year CDs $60,185.24. The single CD wins by $283.22.
Branch — rates fall 1 pp a year: reinvestment rates slide to 4 / 3 / 2 / 1%. The ladder’s locked rungs cushion the fall: $58,632.25 after tax. The roller gets no cushion — $55,644.51. The ladder beats rolling 1-year CDs by $2,987.75 — locked rates are reinvestment-risk insurance. (The single 5-year CD, fully locked at 5.00%, still finishes at $60,774.98.)
Branch — rates rise 1 pp a year: the roller harvests every hike (4.75 → 8.75%): $65,039.76 after tax. The ladder climbs to $62,399.83; the single CD sits at $60,774.98, locked below the new market. Rolling 1-year CDs win by $2,639.93 — locked rates become the anchor when the market pays more.
Branch — cash out at year 2: breaking the single 5-year CD costs one 6-month penalty on the whole balance: $1,378.13, leaving $52,922.56 after tax. Breaking the ladder costs three smaller penalties on the unmatured rungs ($790.89 total) while the 1- and 2-year rungs exit free: $52,812.60 after tax. The single CD still exits with $109.96 more — its higher rate outran the penalty. But if you need only $20,000, the ladder’s matured rungs pay it with zero penalty; the single CD has no partial-withdrawal option.
Branch — 37% federal bracket: the gap shrinks but never flips — $58,702.87 vs $58,474.12, the single CD ahead by $228.75. Taxes scale both legs the same way, so the winner is tax-bracket-proof here.
Branch — 9% state tax on top of 22% federal: $59,531.71 vs $59,281.18 — the single CD ahead by $250.54. Note the contrast with T-bills: Treasury interest is exempt from state tax, so in a high-tax state the bill ladder quietly gains ground (see T-bills vs CDs).
Output · formula · meaning
| Output | Formula | What it means |
|---|
| Ladder 5-yr after-tax total | Σ rung × (1+r)term, maturing rungs at the then-5-yr rate, minus tax | $60,491.76 at the defaults — five locked rungs, reinvested forward; a rung matures every year. |
| Single 5-yr CD after-tax total | $50,000 × 1.055, minus tax | $60,774.98 at the defaults — every dollar earns the highest rung rate, but nothing is touchable for 5 years. |
| Roll-1-yr after-tax total | $50,000 × Π(1 + 1-yr rate each year), minus tax | $60,185.24 flat at the defaults — maximum flexibility, maximum exposure to the rate path. |
| Winner’s edge | best after-tax total − runner-up | $283.22 to the single CD at the defaults — smaller than most people expect, which is the point. |
| Early-exit penalty | 6 months’ interest on each broken balance | $1,378.13 on the single CD vs $790.89 across the ladder’s 3 unmatured rungs — the ladder’s penalty is smaller because its base is smaller. |
| Interest kept after tax | interest × (1 − federal − state) | The ladder keeps $10,491.76 of its $13,450.98 at 22% — CD interest gets no capital-gains break. |
Who uses this
- The retiree parking $50,000 they won’t touch for five years: sees the single CD’s $283.22 edge and locks it in — then keeps a separate emergency fund so the lock never becomes a crisis.
- The rate-watcher betting on cuts: runs the falling-rates branch, sees the ladder beat the roller by $2,987.75, and builds the ladder as reinvestment-risk insurance while keeping yearly liquidity.
- The saver who might need the money early: runs the year-2 exit, learns the ladder’s penalty is $790.89 vs $1,378.13 — and that a partial withdrawal from the ladder costs nothing.
- The high-bracket saver in a high-tax state: adds 9% state tax, watches the gap narrow to $250.54, and checks T-bills vs CDs — where the state-tax exemption lives.
Accuracy & limitations
CD rates are October 2026 snapshots from Bankrate/NerdWallet tables — they change weekly, sometimes daily, and promotional rates can require $10,000 minimums (Popular Direct) or credit-union membership. APYs here assume annual compounding; banks compound daily, which adds a few dollars the calculator ignores. Early-withdrawal penalties vary by bank (6 months’ interest is typical for a 5-year CD; some charge 12 months, some 150 days). Taxes are modeled as a flat marginal rate on the interest, with penalties deducted as forfeited interest — real returns have brackets, phaseouts, and state quirks. Deposits are FDIC-insured to $250,000 per depositor per bank — the $50,000 here is fully covered at one bank, but a bigger ladder should spread across banks. This is educational math, not financial advice.
Cite this calculatorBright Side Kit. “CD Ladder vs Single CD: 2026 Verdict | Bright Side Kit.”
brightoolbox.com, 2026.
Bright Side Kit. "CD Ladder vs Single CD: 2026 Verdict | Bright Side Kit." https://brightoolbox.com/cd-ladder-vs-single-cd/ Accessed October 24, 2026.Data sources- MoneyVerge, “Best CD Rates October 2026” — highest nationally available rates from the Bankrate and NerdWallet tables (APYs as of Oct 9–11, 2026): 1-year 4.75% (E*TRADE), 2-year 4.75% (Barclays), 3-year 4.85% (Popular Direct), 4-year 4.55% (BTG Pactual Bank), 5-year 5.00% (Popular Direct).
- Bankrate, “Current CD Rates” (October 23, 2026) — national average APYs: 1-year 2.17%, 3-year 1.78%, 5-year 1.83%. The top rates on this page pay more than double the average — shopping matters.
- Wall Street Journal, “Today’s CD Rates” (October 23, 2026) — Popular Direct 4.60% 12-month; Tower Federal Credit Union 5.20% 24-month; Toyota Financial Savings Bank 5.25% 60-month (local). Rates move constantly; confirm on the bank’s own site before opening.
- IRS guidance on CD interest — CD interest is taxed as ordinary income in the year it is credited; early-withdrawal penalties are deductible as forfeited interest (an adjustment to income).
- 31 U.S.C. §3124 — Treasury-bill interest is exempt from state and local income tax; CD interest is not — the high-tax-state branch’s whole point.
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Frequently asked questions
Why does the single 5-year CD beat the ladder when rates are flat?
Because the 5-year rate is the highest rung. At October 2026’s top rates, four of the five rungs earn less than 5.00% (4.55–4.85%), so the ladder’s blended return can’t catch a CD that pays the top rate on every dollar. The single CD’s $283.22 edge is just the drag of those four lower rungs. If the curve ever inverts — shorter terms paying more than 5 years — the ladder would flip ahead.
What is reinvestment risk, and how does the ladder protect against it?
Reinvestment risk is the chance that your money matures into lower rates. Rolling 1-year CDs faces it every year: when rates fall 1 point a year, the roller’s 5-year haul collapses to $55,644.51 after tax. The ladder’s rungs locked in at 4.75–5.00% can’t be repriced downward — it finishes at $58,632.25, beating the roller by $2,987.75. Locked rates are insurance you only appreciate when rates fall.
When does rolling 1-year CDs win?
When rates keep rising. If the 1-year rate climbs a point a year (4.75% → 8.75%), the roller harvests every hike and finishes at $65,039.76 after tax — $2,639.93 ahead of the ladder and $4,264.78 ahead of the locked 5-year CD. Flexibility pays when the market keeps offering more than your lock.
What does it cost to break a CD early?
Usually 3–12 months of interest, depending on the term and the bank — 6 months is typical for a 5-year CD. On this page’s $50,000 at year 2: breaking the single 5-year CD costs $1,378.13; breaking the ladder costs $790.89 across its three unmatured rungs (the 1- and 2-year rungs matured penalty-free). The penalty is deductible as forfeited interest on your tax return.
How is a CD ladder taxed?
Every dollar of CD interest is ordinary income — federal and state — in the year the bank credits it. No capital-gains rates, no qualified-dividend treatment. At 22% federal on this page’s ladder, the tax haircut is $2,959.22 of the $13,450.98 in interest. Treasury bills are the contrast: their interest is exempt from state and local tax, which is why the high-tax-state branch points at T-bills vs CDs.
Does it matter which bank issues each rung?
Yes — shop every rung. The national average 5-year CD paid 1.83% in October 2026; the top rate paid 5.00% — on $50,000 that gap is thousands of dollars. Watch the minimums (top rates often need $10,000), and turn off auto-renewal: banks renew matured CDs at whatever rate is posted that day, which is how good ladders quietly become average ones.
Should I build the ladder at one bank or five?
One bank is simpler; five banks can pay more. No single bank tops every term — October 2026’s best 1-year and 5-year rates came from different banks. Splitting rungs across banks chases the top of each term but multiplies the accounts, logins, and 1099-INTs. Either way, stay under the $250,000 FDIC limit per bank, and keep the ladder’s paperwork where your heirs can find it.