What is a Roth conversion calculator?

A Roth conversion calculator estimates the tax cost of moving money from a traditional 401(k) or IRA into a Roth account. GlidePath Money finds your low-tax “Tax Valley” years — the years between when you stop working and when Required Minimum Distributions begin — and shows how much you could convert each year before crossing into the next tax bracket. It shows the numbers; it doesn’t tell you whether to convert.

What is the Roth conversion window, or Tax Valley?

The “Tax Valley” is the stretch of low-income years after you retire but before Required Minimum Distributions (RMDs) push your income back up around age 73–75. Because your tax bracket dips during those years, converting traditional savings to a Roth is usually cheaper then than later. GlidePath maps your specific valley years and the bracket room you have in each.

Does GlidePath tell me whether I should do a Roth conversion?

No. GlidePath shows the math — your valley years, the 12% and 22% bracket headroom, an estimate of tax saved, and the cliffs a large conversion would trip (like IRMAA Medicare surcharges and the Social Security tax torpedo). Whether to actually convert is a decision for you and a CPA or fiduciary advisor.

Is GlidePath Money a subscription?

GlidePath Money is buy-once: $129 for Personal, $199 with the business tools. An optional $39/yr maintenance keeps tax rules and bank parsers current — and if you let it lapse, the app keeps working in full on the version you have. You own it, you don’t rent it.

Roth conversion calculator

When is your Roth conversion window — and what would it cost?

A Roth conversion means moving money from a traditional 401(k) or IRA into a Roth account — you pay tax on it now so it grows tax-free later. The trick is timing: do it in a low-tax year and it’s cheap; do it in a high-tax year and you overpay. GlidePath Money finds your low-tax years for you and shows how much room you have in each — the actual numbers, on your own machine. It shows you the math; it doesn’t tell you whether to convert.

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First, the “Tax Valley” — in plain English.

It’s the cheapest stretch of years you may ever have to move money into a Roth.

Picture the years right after you stop working. Your paycheck is gone, so your income drops — and your tax bracket drops with it. Then around age 73–75, Required Minimum Distributions (the IRS rule that forces you to start pulling money out of traditional retirement accounts, whether you need it or not) kick in, and your taxable income climbs back up. The dip in between is your Tax Valley — usually your lowest-tax years for life.

Here’s why it matters with an example. Say you retire at 63 and your taxable income sits well inside the 12% bracket for a few years. Converting $40,000 from your 401(k) to a Roth while you’re in that 12% bracket costs you about $4,800 in tax. Wait until your 70s, when RMDs have pushed you into the 22% bracket, and the same $40,000 conversion costs roughly $8,800. Same money, a very different bill — the difference is timing.

What GlidePath actually computes.

It maps your valley year by year — not a generic rule of thumb.

Fill in your retirement details once, and the Tax Valley panel lays out a row for every valley year — your age, the phase you’re in, pension and taxable Social Security, your projected 401(k) draw, the bracket you land in, and the headline number: how much you could convert that year before bumping into the next bracket up. It then sums it into four numbers you can read at a glance:

Valley years — how many, and how many sit at the 12% bracket or below.
12% bracket headroom — the total you could convert at the 12% rate across the whole window.
22% bracket headroom — the larger total, if you’re willing to fill the 22% bracket too.
Estimated tax saved — a directional figure for converting now vs. at the higher rates RMDs force later.

GlidePath Money Retirement page showing the success-probability verdict — which names the 9-year Tax Valley between retirement and required withdrawals and the cumulative 22%-bracket room for Roth conversions — above the four headline projection cards. — Your retirement answer, with the Tax Valley built in

It accounts for the things a simple calculator misses.

The Social Security “tax torpedo”

A conversion can drag more of your Social Security into taxable income — so each year’s convertible amount is the real dollars that fit under the bracket top, not a naïve gap. The “tax torpedo” is the name for that effect, and GlidePath folds it in so the headroom number isn’t overstated.

IRMAA Medicare surcharges

Convert too much and you can trip IRMAA — a Medicare premium surcharge that kicks in above an income line, on a two-year lookback. GlidePath flags the year and shows the practical conversion ceiling before that surcharge bites, which is often well below the bracket top.

And it shows its work

A confidence chip tells you how solid the estimate is, and an assumptions panel spells out exactly what the window does and doesn’t model — state tax, the 5-year rules, ACA credits. The headroom is a ceiling to explore, never a black-box answer to take on faith.

The honest part: it shows, it doesn’t advise.

A Roth conversion has tradeoffs no calculator can decide for you.

GlidePath shows you the valley, the headroom, the estimated savings, and the cliffs to watch. What it deliberately doesn’t do is tell you to convert, or how much. Treat the headroom number as a ceiling you could explore, not a recommendation. The right move depends on things outside the app — your health, your heirs, your state, your read on future tax rates — so the conversation about what to actually do belongs with a CPA or a fee-only fiduciary advisor.

The Roth window is one of five retirement questions GlidePath answers — alongside “will my money last,” when to claim Social Security, and how to bridge to Medicare if you retire before 65. They all read from the same numbers, so a change in one updates the others.

Common questions.

Is this a free Roth conversion calculator?

It’s part of GlidePath Money, which is a one-time purchase — $129 for Personal — not a subscription you rent. An optional $39/yr keeps tax rules current, but the app keeps working in full whether or not you ever pay again. You own it.

Does my financial data leave my computer?

No. GlidePath is local-first — the Tax Valley math runs on your own machine, from plain files you own. Your balances and income aren’t uploaded anywhere to run this calculation.

What years does it cover?

It maps the multi-year window between when you retire and when RMDs begin (around age 73–75), with a row for each valley year and a running total of the bracket room across the whole window.

See your own Tax Valley.

$129 one-time for Personal, $199 for Personal + Business. Optional $39/yr keeps you current; stop any time and the app keeps working — in full, forever.

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GlidePath shows you the math — estimates only, not tax or investment advice. Roth conversions have tradeoffs (the 5-year rules, state tax, IRMAA, ACA credits) the app flags but doesn’t fully model; for your specific situation, talk to a fiduciary advisor or CPA.