Comprehensive Guide
Learn more in our Investing Guide.
How it works
A Roth conversion ladder is the early-retiree tactic of moving traditional money into Roth deliberately, one tax bracket at a time, during low-income years. The mechanics are simple subtraction: your other taxable income plus the standard deduction leaves headroom below whichever bracket ceiling you target, and that headroom is the year's ideal conversion size. Convert more and the overflow is taxed at higher marginal rates — the mistake the ladder exists to prevent. Each converted amount also starts its own five-tax-year clock before it can be withdrawn penalty-free before age 59½, which is how year-one conversions become spendable in year six and bridge the gap to penalty-free access. This calculator sizes the annual fill, estimates the tax at your assumed marginal rate, and lays out the whole multi-year schedule until the traditional balance empties or the window closes. Bracket tops, deduction amounts and surtaxes like ACA premium subsidies or IRMAA move constantly, so treat every default here as an illustrative placeholder and re-run the plan each December.Formula
Headroom = bracket top − max(0, other income − deduction) | Conversion = min(headroom, balance ÷ years) | Est. tax = conversion × marginal rate
Tips
- Pay the tax from outside funds so the full converted amount compounds tax-free.
- Stop filling when ACA subsidies, IRMAA surcharges or state cliffs would eat the savings.
- Each conversion seasons five tax years before penalty-free early withdrawal — stagger them.
- Re-run the plan every December against current bracket tables, not old defaults.
- Leave enough traditional money to fill low brackets later in retirement.