Roth conversion ladder calculator

Roth conversion ladder — the FIRE community's most powerful tax tool

A Roth conversion ladder is the strategy of systematically converting traditional IRA or 401(k) dollars to a Roth IRA during years when your income is low — typically the early retirement years between leaving work and starting Social Security or required minimum distributions (RMDs). Done correctly, it allows you to pay taxes at 12% or 22% now rather than 28–37% later when RMDs force large mandatory withdrawals.

Why early retirees use this strategy

Consider someone who retires at 50 with $1M in a traditional IRA. From age 50–59, their taxable income may be very low — perhaps just living expenses from a brokerage account. This creates a window to convert $50,000–$80,000 per year into Roth at the 12% bracket. Without a conversion strategy, that $1M grows to $2M+ by age 73, generating RMDs of $100,000+/year — pushing the retiree into 22–28% brackets for life and potentially affecting Medicare premiums and Social Security taxation.

The FIRE (Financial Independence, Retire Early) community has documented this extensively. The math consistently shows that bracket-filling conversions during the gap years save hundreds of thousands of dollars in lifetime taxes for people with large traditional accounts.

The 5-year rule — nuances matter

There are actually two separate Roth 5-year rules, and confusing them is a common mistake:

1. Roth IRA contributions 5-year rule: Earnings on Roth contributions can't be withdrawn tax-free until 5 years after the first year you contributed to any Roth IRA. This clock starts once and never resets.
2. Roth conversion 5-year rule: Each converted amount has its own separate 5-year clock. The converted principal (not earnings) can be withdrawn penalty-free after 5 years — even before age 59½. This is the clock that matters for a conversion ladder.

After age 59½, both rules are irrelevant for tax/penalty purposes — all Roth withdrawals are tax-free and penalty-free as long as the account has been open for at least 5 years.

Roth conversion for estate planning

A Roth IRA passed to heirs is an extraordinary estate planning tool. Under the SECURE Act (2019) and SECURE Act 2.0 (2022), most non-spouse beneficiaries must deplete inherited IRAs within 10 years (the "10-year rule"). A large inherited traditional IRA can be brutal for a beneficiary in peak earning years — adding $100k+ of ordinary income annually. An inherited Roth IRA has the same 10-year distribution requirement, but all distributions are tax-free. Converting to Roth before death eliminates the income tax burden from your heirs entirely.

IRMAA risk at high conversion amounts

Medicare Income-Related Monthly Adjustment Amounts (IRMAA) add surcharges to Part B and Part D premiums when modified adjusted gross income exceeds thresholds. In 2024, the surcharges begin at $103,000 (individual) or $206,000 (married, filing jointly) and escalate in tiers up to $500k+ MAGI. A large Roth conversion in a single year can cost $4,000–$16,000 in additional Medicare premiums the following year. For those on Medicare, stay alert to IRMAA cliff points when sizing annual conversions.

Alternatives to large RMDs

For those who don't want to convert aggressively, qualified charitable distributions (QCDs) allow IRA owners age 70½+ to donate up to $105,000/year (2024) directly from an IRA to a qualified charity, satisfying RMD requirements without the amount appearing as taxable income. QCDs are extremely tax-efficient for charitably inclined retirees and can complement a conversion strategy.