Roth Conversion Ladder Calculator: The Early Retirement Tax Strategy

The problem with early retirement and a 401k: withdrawing before age 59.5 triggers a 10% penalty on top of ordinary income tax. A $50,000 withdrawal becomes $37,000 after a 26% tax rate and 10% penalty combined.

The Roth conversion ladder solves this. Convert 401k funds to a Roth IRA each year while income is low. Wait 5 years. Withdraw the converted amount tax-free, with no penalty, at any age.

How the Ladder Works

The Roth conversion ladder is a 5-year rolling process:

Year 0 (retire): Identify how much you need in Year 5 of retirement. Convert that amount from traditional 401k/IRA to Roth IRA. Pay income tax on the conversion at your current (low) tax rate.

Years 1-4: Live off taxable brokerage accounts, Roth contributions (contributions, not gains, are always accessible), or other assets while the converted amount seasons.

Year 5: Withdraw the Year 0 conversion amount from Roth IRA. Tax-free. Penalty-free.

Each year: Convert the next layer of the ladder (what you will need in 5 years).

The ladder runs continuously. Each year you make a new conversion. Each year the 5-year-old conversion becomes available.

The Tax Math

The key advantage: converting in years when income is low means paying low or zero tax on the conversion.

Example: Retire at 45 with $1,200,000 in a traditional 401k. Need $60,000/year in expenses. Taxable brokerage will cover years 1-5.

In year 1 of retirement, convert $60,000 to Roth. Your income is only the $60,000 conversion (no W-2 income). Federal tax on $60,000 for a single filer in 2026 (after standard deduction of $15,000): tax on $45,000 = approximately $5,200 (12% bracket).

At 45, paying $5,200 to access $60,000 penalty-free in year 5 is a 8.7% effective conversion cost. Far better than the 26-36% combined tax + penalty rate from a direct early withdrawal.

Zero-Tax Conversions

In low-income years, Roth conversions can be nearly or entirely tax-free.

Example: Married filing jointly, two early retirees with no W-2 income.

Standard deduction (2026): $30,000

If you convert $30,000 from traditional to Roth, the taxable income is $0. You pay nothing on a $30,000 conversion. That is $30,000 moved from tax-deferred to tax-free with zero current tax.

Converting up to the top of the 12% bracket (approximately $104,000 for MFJ) keeps the effective rate on additional conversion dollars at just 12%.

Building a Full 5-Year Ladder

For $60,000/year needed from Roth after year 5, you need to convert $60,000 in each of years 0-4.

| Year | Action | Taxable (Covers) | |------|--------|-----------------| | 0 | Convert $60,000 (available year 5) | Draw from brokerage | | 1 | Convert $60,000 (available year 6) | Draw from brokerage | | 2 | Convert $60,000 (available year 7) | Draw from brokerage | | 3 | Convert $60,000 (available year 8) | Draw from brokerage | | 4 | Convert $60,000 (available year 9) | Draw from brokerage | | 5 | Withdraw year-0 conversion | Continue ladder |

You need 5 years of taxable brokerage or Roth contributions to bridge the initial gap. This is why FIRE planning includes a taxable brokerage account, not just retirement accounts.

SEPP as an Alternative

Substantially Equal Periodic Payments (SEPP, also called Rule 72(t)) is an alternative for accessing 401k before 59.5 without penalty. It requires taking calculated distributions for at least 5 years or until age 59.5, whichever is longer.

SEPP is less flexible than the conversion ladder. Once started, you cannot change the distribution amount without triggering penalties on all prior distributions. The ladder allows more control over timing and amount.

For early retirees with enough non-retirement assets to bridge 5 years, the conversion ladder is generally superior. For those who need access immediately from retirement accounts, SEPP may be necessary.

ACA Subsidy Interaction

Roth conversions count as income for ACA healthcare subsidy eligibility. Converting $60,000 in a low-income year may push MAGI above the subsidy cliff.

ACA premium tax credits phase out as income rises. In 2026, a 45-year-old individual pays roughly $400/month for a bronze plan with maximum subsidies (at ~$21,000 income) vs. $900/month without subsidies (at $65,000 income). A large conversion can cost $6,000 per year in lost healthcare subsidies.

Optimize conversions to stay below the subsidy reduction threshold, or model the full cost of conversions above it. This is the most complex part of early retirement tax planning.

Frequently Asked Questions

Does the 5-year clock reset with each conversion?

Yes. Each conversion has its own separate 5-year clock. The Year 0 conversion becomes accessible in Year 5. The Year 1 conversion becomes accessible in Year 6. They do not share a single clock.

Can I build a Roth conversion ladder with a Roth 401k?

Roth 401k contributions are accessible after 59.5 without penalty, but early access still has restrictions unless rolled to a Roth IRA first. Roll the Roth 401k to a Roth IRA before retirement to access contributions (not gains) immediately and start the conversion ladder with traditional balances.

What happens to unconverted traditional IRA/401k funds in early retirement?

They continue growing tax-deferred. At 59.5, they become accessible without penalty. At 73, Required Minimum Distributions begin. Many early retirees end up with large RMDs because they could not convert fast enough in low-income years. Running projections to age 80+ helps optimize how aggressively to convert.