Roth Conversion Ladder Bridge Calculator

A Roth conversion ladder moves money out of traditional accounts a year at a time, but each conversion has to season for five years. This shows what has to fund those five years.

Bridge funding you need outside the ladder

—

Suggested annual conversion: —
First conversion unlocks at age: —
Conversion years the ladder needs: —

What you spend against what the ladder has unlocked

Three running totals from the year you stop working.

Spending to cover before 59½ Unlocked by seasoned conversions Funding you supply yourself Bridge funding needed

The ladder, year by year

Ladder year	Your age	Converted that year	Becomes accessible	That year's spending comes from

What this calculator leaves out

Two known simplifications, stated plainly, because getting either one wrong costs real money.

The tax on the conversion itself

Every dollar you move from a traditional account into a Roth is ordinary income in the year you move it. This page does not model one cent of that. It sizes the mechanism and the timing, not the tax bill, and the tax bill is usually what decides how big each conversion should be.

What a real plan has to weigh, and what is missing here:

Your marginal rate that year. A conversion stacks on top of every other dollar of income you have. Convert enough and part of the conversion lands in a higher bracket than the one it started in.
Marketplace health insurance. Premium tax credits under the ACA are calculated from modified adjusted gross income, and a conversion raises it. A conversion that looks free on this page can cost thousands in credits you no longer qualify for.
The gains you realize funding the bridge. Selling taxable holdings to pay for the bridge years creates capital gains in the same years you are converting. Both land on the same return and they interact.
State income tax. Some states tax the conversion, some do not, and moving between them changes the answer.
Where the tax payment comes from. Paying the conversion tax out of the converted money shrinks what actually lands in the Roth, so the ladder needs larger conversions than this page suggests.
After-tax basis. If part of your traditional balance is after-tax money, the pro-rata rule decides how much of each conversion is taxable, and it looks at all your traditional IRAs together rather than at the one you converted from.

Sizing each conversion to fill a tax bracket, rather than to match a year of spending, is the usual refinement. That is a question for a CPA or a fee-only advisor who can see your whole return, not for a calculator with three inputs.

The fine print on the five-year clock

The clock starts on January 1 of the conversion year, not on the day of the conversion. A conversion made in December seasons in a little over four calendar years; the same conversion made a few weeks later, in January, takes nearly five. This page uses a flat five years for every conversion.
Every conversion carries its own clock. They do not stack, and finishing the first one does nothing for the second. That is why a ladder is a ladder: one rung a year, each waiting out its own five years.
Contributions, conversions and earnings follow different rules. Money you contributed directly to a Roth can come out at any time. Converted amounts are the ones with the five-year wait. Earnings are different again, and generally need both age 59½ and a Roth account at least five years old before they come out tax free.
The conversion clock stops mattering at 59½. Past that age the wait is no longer the constraint, which is exactly why the bridge is a problem that ends.
A ladder is not the only route. Substantially equal periodic payments under section 72(t), and the rule that lets you draw from the 401(k) at a job you leave in or after the year you turn 55, both exist and both have their own trade-offs. This page does not compare them.

None of this is advice, and none of it replaces reading the rules or hiring someone who already has. It is a description of a mechanism, so that the arithmetic above makes sense.

Stop re-typing your numbers

This page is a snapshot from figures you keyed in by hand. Ember keeps the same numbers current on their own: every account in one ledger, real net worth, and spending you can actually trust.

Ember is in private beta and invite-only right now.

This tool provides estimates for general planning purposes only, not personalized financial or tax advice. It relies on simplifying assumptions (see "How this is calculated" below) that will not match your actual results. Consult a qualified professional before making financial decisions.

How this is calculated

The formula

bridge years                = min(5, max(0, 59½ − age you stop working))
bridge funding needed       = annual bridge spending × bridge years
suggested annual conversion = annual bridge spending × min(1, conversion years needed)
first conversion unlocks at = (age you stop working) + 5
conversion start age        = (age you stop working) − 5
conversion years needed     = max(0, 54½ − age you stop working)
conversion years funded     = traditional balance ÷ annual bridge spending

conversion start age is the other way to read the question. To have a conversion already seasoned on the day the paycheck stops, the first one has to be made five years before that day, while you are still working. This page does not assume that, because converting on top of a salary is taxed at the rate the salary already puts you in. The figure is shown under the headline for the age you entered, and choosing not to do it is precisely what creates the bridge.

The ladder itself is a loop, one rung per year, and it stops at 59½:

for each ladder year N = 1, 2, 3, ... until age 59½:
    age       = (age you stop working) + N − 1
    convert   = min(what the year N + 5 rung will need,
                    traditional balance left)
    accessible in year N + 5, at age (age you stop working) + N + 4

    year N is paid for by:
        taxable or Roth contribution money,   if N <= 5
        the conversion made in year N − 5,    if N > 5

"What the year N + 5 rung will need" is a full year of spending for every rung that lands before 59½, and nothing at all for one that lands after it. The single exception is the year 59½ falls inside, which needs half a year.

Why the bridge is not always five years

This page originally sized the bridge at a flat five years of spending for everybody. That is right only while 59½ is more than five years away. Traditional accounts become available at 59½ whether or not a single conversion has seasoned, so the bridge cannot outlast the distance to 59½:

bridge years          = min(5, max(0, 59½ − age you stop working))
bridge funding needed = annual bridge spending × bridge years

Stop at 54 or younger and the two readings agree, and the bridge is five years. Stop at 55 and it is 4.5 years. Stop at 58 and it is 1.5 years, not five. At $55,000 a year that is the difference between $82,500 and $275,000, so at 58 the flat version overstates what has to be set aside by more than three times. The overstatement shrinks as the stop age falls, to about a tenth at 55, and disappears at 54.

The same bound runs through the rest of the page. A conversion made after age 54 unlocks at 59½ or later, when it is no longer the thing standing between you and the money, so the schedule stops asking for one, the table ends at 59½, and the chart flattens there.

Why five years

Money in a traditional 401(k) or IRA generally cannot be withdrawn before 59½ without a 10% additional tax on top of the ordinary income tax you already owe on it. Converting that money to a Roth is not a withdrawal, so the additional tax does not apply to the conversion. The converted amount then has to sit in the Roth for five years before you can take it out without that same 10% applying to it.

Convert one year of spending every year and, from year six onward, there is always a conversion coming due. Before year six there is not, and that is the whole problem this page measures. It is also a problem with an end date: at 59½ the traditional balance is available directly, so the rungs stop mattering and the page stops counting them.

Where the bridge money comes from

Two sources cover the bridge years without the extra tax:

A taxable brokerage account. No age rules of any kind. You owe capital gains tax on what you sell, and nothing beyond that.
Roth contributions you already made. The amount you put in directly, not the earnings it produced, can be withdrawn at any age. Conversions are the part with the five-year wait; direct contributions are not.

Cash works too, at the cost of parking five years of spending in something that earns very little for as long as you hold it.

What this model assumes

No taxes anywhere. The largest simplification by far, and the one the section above is entirely about.
Flat spending. One annual figure carries across every bridge year. Health insurance alone often makes the bridge years the most expensive ones.
No growth on the traditional balance. How many years of spending the balance covers is a straight division. In reality the part you have not converted yet keeps growing, which stretches that figure, sometimes by a lot.
No growth on the bridge money either. The bridge is quoted in today's dollars. Money you are about to spend tends to be held conservatively, so this is close to right, but it is still an assumption.
Whole years, with one exception. Ages and rungs are counted in whole years, so a fractional age you type is read to the nearest one. The only half on the page is 59½ itself: the year it falls inside needs half a year of funding rather than a whole one.
A conversion every single year, at exactly one year of spending. Real ladders skip years, double up, and get sized to a tax bracket rather than to a grocery bill.
Nothing else pays the bills. Part-time income, a spouse still working, or rental income all shrink the bridge. The Barista FIRE calculator is the tool for the part-time case.

What this page is not

It describes a mechanism and does the arithmetic behind it. It does not tell you whether a conversion ladder suits your situation, how large your conversions should be, or what any of it will cost you in tax. Those answers depend on your whole tax return and on rules that change. Take them to a qualified professional.

Shared assumptions

Returns are real, not nominal. Every return figure on this page is already inflation-adjusted, so all dollar amounts are in today's money. There is no separate inflation input to set.
Returns are smooth. The same return is applied every year. Real markets are not smooth, and the order in which good and bad years arrive changes outcomes materially.
No taxes, fees, or lumpy spending. Investment fees, taxes on withdrawals, one-off costs, and changes in your spending over time are not modelled.
Nothing leaves your browser. The whole calculation runs client-side. We do not receive, log, or store anything you type.