IRA vs Roth IRA Calculator

The whole question is one comparison of two rates

Strip away the folklore and the IRA question is one inequality. A traditional contribution lets you avoid tax at your rate today and pay it at your rate in retirement. A Roth does the opposite: you pay today and withdraw tax-free. So the traditional wins when your retirement rate is lower than your current rate, the Roth wins when it is higher, and the two are identical when the rates are equal. The break-even figure printed above is exactly that crossover, and you can watch it move as you change your assumptions: raise your expected retirement rate above your current one and the Roth takes over.

What makes this hard in practice is that the two rates are not the same kind of number. Your current rate is knowable — it is the rate on your last dollar of income, and the brackets are published. Your retirement rate is a forecast about a household you have not met yet: what you will withdraw, what Social Security will pay, whether you will still be married, whether you will have moved, and what the brackets will look like after three more decades of legislating. Anyone who states that forecast with confidence is guessing, which is why this page shows the whole curve rather than a single answer.

The comparison that makes the Roth look better than it is

Most comparisons contribute the same dollar amount to each account: $7,500 traditional against $7,500 Roth. But those are not the same sacrifice. The traditional contribution comes out of your income before tax, so at a 22% marginal rate it only costs you $5,850 of take-home pay; the Roth contribution costs the full $7,500. The traditional saver is $1,650 ahead the moment the contribution is made, and comparing the two balances ignores it. This calculator spends the same money on both sides instead.

That also explains the capped case, which is the norm rather than the exception: once the gross-up hits the IRS limit, the traditional route cannot absorb the whole budget, and the remainder has to go somewhere. Here it goes into a taxable account, growing at a reduced rate and paying capital gains at the end — which is what would actually happen, and which is less flattering to the traditional side than pretending the money vanished. When the numbers are close, that side account is often what decides the answer.

When the traditional deduction disappears

A traditional IRA contribution is always allowed, but it is only deductible if you meet the coverage and income tests: if neither you nor your spouse is covered by a retirement plan at work, it is fully deductible at any income. If you are covered, the deduction phases out over an income range that depends on your filing status. For 2026 a single filer covered by a plan loses the deduction between $81,000 and $91,000 of MAGI; a married couple where the contributing spouse is covered, between $129,000 and $149,000; and where the contributor is not covered but the spouse is, between $242,000 and $252,000.

Inside a band the deduction does not vanish, it shrinks — the mechanism is pro rata, so at the midpoint of the band half the contribution is deductible. That is the default scenario on this page, and it is the case that produces the most interesting answer: the gross-up is halved, the traditional contribution gets capped earlier, and the Roth wins on the arithmetic even though the saver's current rate is comfortably above the expected retirement rate. Above the top of the band, a traditional contribution is the worst of both worlds: no deduction going in, full income tax coming out.

Eligibility, and the backdoor

Roth contributions have their own income test, and for 2026 the phase-out runs from $153,000 to $168,000 for a single filer or head of household and from $242,000 to $252,000 for a married couple filing jointly. Contributions phase out across the band and stop at the top of it. Married filing separately is treated harshly: the range is $0 to $10,000, which means a direct Roth contribution is effectively unavailable for most separate filers.

Above the range the usual route is a backdoor conversion — a non-deductible traditional contribution followed by a conversion to Roth. The contribution was already taxed, so converting it is largely tax-free. Two things to know before doing it. The pro-rata rule aggregates every pre-tax IRA you own, so if you hold a large rollover IRA, most of each conversion is taxable in proportion to the pre-tax share, and the paperwork is unforgiving. And if you have large pre-tax balances, the better answer is often not a backdoor at all but a 401(k) that accepts rollovers, which clears the way for clean conversions afterwards.

The argument that is not about rates: RMDs

Everything above assumes the two accounts are otherwise identical, and they are not. A traditional IRA is subject to required minimum distributions from the applicable age — 73 for anyone born from 1951 to 1959, and 75 for anyone born in 1960 or later. From then on a rising percentage of the balance must come out every year and is taxed as ordinary income, whether you need it or not. A Roth IRA has no lifetime RMD at all.

That forced income has consequences the arithmetic above cannot capture. It can push you into a higher bracket in the years you can least control, it can increase the taxable share of your Social Security, and it can raise your Medicare premiums through the income-related surcharge two years later. It also matters for whoever inherits the account: a Roth left to a non-spouse heir keeps its tax-free character, while a traditional IRA hands the heir a tax bill attached to a ten-year withdrawal deadline. At or near equal rates these arguments favour the Roth, and they are the honest reason a saver with a high current rate might still choose one. If the balance is large, the distribution schedule is worth running on its own.

Frequently asked questions

Is a Roth IRA always better than a traditional IRA?

No, and the claim is easy to disprove. If your marginal rate in retirement is lower than it is today, a traditional contribution wins, because you skipped a bigger tax now and pay a smaller one later. If your rate is higher in retirement the Roth wins. The calculator prints the break-even retirement rate: below it the traditional wins, above it the Roth does. What makes the Roth look better in most calculators is not tax maths but an unfair comparison — the same dollar amount contributed to each account, when the traditional dollar cost less out of pocket.

What is the 2026 IRA contribution limit and catch-up?

The 2026 IRA contribution limit is $7,500, with an additional $1,100 catch-up for those aged 50 or older, for a total of $8,600. The limit is shared across all your IRAs — traditional and Roth together — so $7,500 is the ceiling for the two combined, not per account. This calculator reads those figures from the same IRS dataset the retirement calculator uses, so the limit is enforced rather than typed into the page.

When is a traditional IRA contribution no longer deductible?

Only if you or your spouse is covered by a retirement plan at work, and your income is above the phase-out range for your filing status. For 2026 those ranges are $81,000 to $91,000 for a single filer or head of household covered by a plan, $129,000 to $149,000 for a married couple where the contributing spouse is covered, and $242,000 to $252,000 for a married couple where the contributor is not covered but the spouse is. Inside a range the deduction is phased out pro rata, not switched off; above it, a contribution is still allowed but buys no deduction.

Can I contribute to a Roth IRA at any income?

No. For 2026 the Roth IRA contribution phases out between $153,000 and $168,000 of modified adjusted gross income for a single filer or head of household, and between $242,000 and $252,000 for a married couple filing jointly. Married filing separately phases out between $0 and $10,000. Above the top of the range a direct contribution is not permitted — which is what a backdoor Roth conversion works around.

What is a backdoor Roth conversion?

A non-deductible traditional IRA contribution followed by a conversion to Roth. The contribution has already been taxed, so the conversion of that amount is largely tax-free. It is not free of complications: the pro-rata rule aggregates all your pre-tax IRA money, so if you hold a large traditional or rollover IRA, most of any conversion is taxable in proportion to the pre-tax share. It also does nothing about a large pre-tax balance you already hold.

Why does the traditional account force money out and the Roth not?

Required minimum distributions. From the applicable age — 73, or 75 if you were born in 1960 or later — a traditional IRA must distribute a rising percentage of its balance each year whether you need the money or not, and the distribution is ordinary income. A Roth IRA has no lifetime RMD. That forces income into retirement years, can push you into a higher bracket, can increase the taxable share of your Social Security, and can raise your Medicare premium two years later.

Does the state income tax change the answer?

It can, and this comparison uses federal rates only. If you pay state income tax now and will retire in a state with no income tax, the traditional contribution escapes a higher combined rate today and is taxed at a lower one later, which strengthens the traditional case. Moving the other way — earning in a no-tax state and retiring in a taxing one — strengthens the Roth. A handful of states also do not follow the federal treatment of retirement contributions and withdrawals, so the state line belongs in the decision even though it is not in this model.

Reading the charts

The left chart plots each account's after-tax value against the retirement tax rate, holding everything else at your inputs. The traditional line slopes down — every point of future tax costs it — while the Roth line is flat, because its withdrawals are not taxed. The crossing point is the break-even, and it is the only number on this page that answers the question cleanly. The right chart leaves the arithmetic behind and shows the structural difference the comparison cannot price: the annual distribution the traditional balance forces once it reaches the applicable age, and the tax it generates at your assumed retirement rate. A Roth IRA's line would be flat on the axis.