The key differences between a Roth and traditional IRA

By Nicolas StrautPublished August 21, 20269 min read

Key takeaways

A traditional IRA and a Roth IRA share the same contribution limit, $7,500, or $8,600 if you are 50 or older, and then tax the money at opposite ends.¹
The main difference between a Roth and traditional IRA is when you pay the tax: a traditional IRA defers it to withdrawal, a Roth prepays it, and at the same marginal rate both produce exactly the same after-tax result.
Tweed's retirement calculator turns a guess about your future tax bracket into an actual number, which is the one input this whole decision depends on.

In this article

Roth vs traditional IRA at a glance
What are the 6 key differences between a Roth IRA and a traditional IRA?
What are the income limits for a Roth and a traditional IRA?
How to work out your break-even tax rate
How to choose between a Roth and a traditional IRA
Can you contribute to both a Roth and a traditional IRA?
Which provider should you choose for your IRA?
Frequently asked questions about Roth and traditional IRAs
Related posts

A traditional IRA gives you a deduction now and taxes the withdrawal later. A Roth gives you no deduction and never taxes the withdrawal. If your tax rate is the same in both years, the two produce identical results, and the whole decision comes down to which rate is higher, now or later.

Roth vs traditional IRA at a glance

A traditional IRA runs on IRC §408 and a Roth IRA on IRC §408A, and every other difference between them follows from that split.²

	Traditional IRA	Roth IRA
Contributions	Pre-tax if deductible, otherwise after-tax with basis	Always after-tax
Qualified withdrawals	Taxed as ordinary income	Not taxed
Contribution limit	$7,500, or $8,600 at 50+	$7,500, or $8,600 at 50+
Income limit on contributing	None, with earned income	Yes, by MAGI
Income limit on deducting	Yes, if covered by a workplace plan	Not applicable, never deductible
Lifetime required minimum distributions	Yes*	None for the original owner
Withdrawing your own contributions early	Taxed, plus 10% unless an exception applies	Any time, tax-free and penalty-free

The $7,500 limit above is combined across every IRA you own, not a separate cap per account.
*RMD ages run 73 for those born 1951 to 1958 and 75 for those born 1960 or later. The 1959 cohort is unresolved: the statute is internally inconsistent, the regulation covering it is formally reserved, and the proposed rule that would set the age at 73 has not been finalized. What a traditional IRA is has the full picture.

What are the 6 key differences between a Roth IRA and a traditional IRA?

There are six meaningful differences between a Roth IRA and a traditional IRA, and every one of them traces back to a single choice: when you pay the tax.

When you pay the tax

This is the difference that matters mathematically: a traditional IRA defers it, a Roth prepays it, and every item below follows from that one choice.

Whether you can contribute at all

A Roth has an income ceiling. A traditional IRA does not, as long as you have earned income.

Whether you get a deduction

A traditional contribution is deductible only if you and your spouse fall outside the workplace-plan phase-out. A Roth contribution is never deductible, by design.

Whether you are forced to take the money out

A traditional IRA carries lifetime required minimum distributions; missing one now costs 25%, or 10% if corrected within the window, down from 50% before SECURE 2.0.³ A Roth has none for the original owner, which is also why it survives longer as an estate asset.

How easily you can reach the money early

Roth contributions, though not earnings, come out at any age tax-free and penalty-free, because the tax was already paid.⁴ Traditional withdrawals before 59½ are ordinary income plus a 10% penalty unless an exception applies.

What your heirs receive

Both accounts follow the 10-year rule for most non-spouse beneficiaries, but a traditional IRA lands as ordinary income during what are often the heir's peak-earning years, and a Roth does not.

What are the income limits for a Roth and a traditional IRA?

There are two different income limits attached to an IRA, and they get confused constantly: one decides whether you can contribute to a Roth at all, and the other decides only whether a traditional contribution is deductible.

Can you contribute to a Roth IRA this year?

Yes, as long as your income falls under the limit for your filing status, since this limit decides whether you may contribute at all.

Filing status	Full contribution below	Phase-out range	Ineligible at or above
Single or head of household	$153,000	$153,000 to $168,000	$168,000
Married filing jointly	$242,000	$242,000 to $252,000	$252,000
Married filing separately, living with spouse	n/a	$0 to $10,000	$10,000

Above the ineligible threshold you cannot contribute to a Roth directly, but converting a nondeductible traditional contribution afterward has no income limit. Backdoor Roth IRA covers that route and the pro-rata rule that comes with it.

Can you deduct a traditional IRA contribution this year?

Whether you can deduct a traditional IRA contribution depends only on workplace-plan coverage for you or your spouse, and it applies only to the deduction, never to whether you can contribute.

Situation	Full deduction below	Phase-out range	No deduction at or above
Single or HOH, covered by a plan	$81,000	$81,000 to $91,000	$91,000
MFJ, contributor covered by a plan	$129,000	$129,000 to $149,000	$149,000
MFJ, contributor not covered, spouse is	$242,000	$242,000 to $252,000	$252,000
Neither spouse covered by a plan	No limit	n/a	n/a

You can always contribute to a traditional IRA if you have earned income. There is no income ceiling on contributing, only on deducting, so nothing stops someone earning $400,000 from putting $7,500 into a traditional IRA.
A nondeductible contribution creates basis, which means filing Form 8606 every year for the life of the account and pro-rata exposure on any future withdrawal or conversion. It is the least attractive outcome, and the one people back into by accident.
Coverage is determined by whether you were an active participant for any part of the plan year, not the whole year, and your W-2 box 13 is the indicator.⁵ What a traditional IRA is walks through that test in full.

How to work out your break-even tax rate

Your break-even tax rate is simply your current marginal rate: above it, a traditional IRA wins, and below it, a Roth wins. That is true because of a simple identity: if your marginal tax rate is the same in the year you contribute and the year you withdraw, a traditional IRA and a Roth IRA produce identical after-tax dollars. Multiplication is commutative, so taxing before growth and taxing after growth land at the same number when the rate does not change.

The formula behind that identity is not complicated. A traditional IRA gives you your contribution, multiplied by growth, multiplied by one minus your future tax rate. A Roth gives you your contribution, multiplied by one minus your current tax rate, multiplied by the same growth, so the only difference between the two is which rate gets subtracted.

What $7,500 looks like at four different withdrawal rates

A single $7,500 contribution at a 22% current marginal rate, invested for 30 years at 7%, grows to $57,092 before tax. The traditional column assumes the full $7,500 is invested pre-tax and taxed on the way out. The Roth column assumes that same pre-tax income is taxed at 22% first, so only $5,850 actually gets invested.

Marginal rate when you withdraw	Traditional, after tax	Roth, after tax	Which wins
12%	$50,241	$44,532	Traditional
22%, same as today	$44,532	$44,532	Neither, exactly equal
24%	$43,390	$44,532	Roth
32%	$38,823	$44,532	Roth, by more

Why $7,500 in a Roth is more money than $7,500 in a traditional IRA

Both accounts share the same $7,500 ceiling, but Roth dollars are already after-tax and traditional dollars are not, so filling a Roth shelters more real purchasing power. The fair comparison is $7,500 in a Roth against $7,500 in a traditional IRA plus the deduction's tax savings invested separately, where that side account then owes its own tax every year. This only matters if you reliably max out; for anyone contributing less, the asymmetry is irrelevant.

What state income tax does to the answer

Your break-even rate is federal plus state, and state rates can move the answer by more than a full bracket. Contributing in a high-tax state and later retiring somewhere with no state income tax pushes hard toward a traditional IRA, and the reverse pushes toward a Roth. Several states also exempt some retirement income outright, a third variable and a good reason not to over-engineer the forecast.

How to choose between a Roth and a traditional IRA

Neither account is better in general. The arithmetic above decides it, and the conditions below just describe when that arithmetic tips each way.

The arithmetic favors a Roth when: you are early career in the 10% or 12% bracket, expect your income to rise, already max out and want the larger real amount, or want no lifetime RMDs.
The arithmetic favors a traditional IRA when: you are in peak earning years at 24% or above, qualify for a full deduction, and expect meaningfully lower income in retirement.
When your income makes the choice for you: above the Roth ceiling you cannot contribute directly, and above the deduction ceiling a traditional contribution buys basis instead of a deduction, which is exactly what backdoor Roth IRA solves.
A deliberate split: holding both account types buys you control over which one you draw from in a given year, which lets a retiree manage their own bracket after they stop working.
A larger conversion or withdrawal can raise Medicare premiums two years later through IRMAA, and can pull more of your Social Security benefit into taxable income;Roth conversion covers both in full.

What to do if you cannot guess your future tax rate

If you cannot forecast your bracket three decades out, that is normal, and three things are still true and useful without a forecast.

"My bracket in retirement" is not a single number, since traditional withdrawals fill the standard deduction and the lower brackets first, so the effective rate on those dollars usually runs below your current marginal rate.
A split between the two is a real answer, not a hedge against thinking. It gives you a lever to pull later, and a retirement calculator shows how each choice compounds.
Uncertainty tilts slightly toward a Roth, since a Roth also hedges future statutory rate changes and removes RMD pressure, though only slightly.

Can you contribute to both a Roth and a traditional IRA?

Yes, you can contribute to both in the same year. What you cannot do is contribute the full limit to each one, since the $7,500 ceiling, or $8,600 at 50 or older, applies across every IRA you own.

You can split $3,750 into each account without issue, but $7,500 into each one is an excess contribution.
The split is the practical form of the tax-diversification argument above, and the only version of "I don't know my future rate" that requires no forecast at all.
An excess contribution costs 6% of the amount over the limit for every year it stays in the account. What a Roth IRA is covers how to fix one.

Which provider should you choose for your IRA?

For a mainstream IRA at a large brokerage, the account itself is free almost everywhere, so the provider matters far less than the two decisions above it: Roth or traditional, and what you actually invest in.

The fund menu, and whether the provider's own index funds carry a fee.
Whether fractional shares are supported, which matters for small or irregular contributions.
Whether there is an automated investing option, and what it charges annually.
How the provider handles a backdoor Roth conversion, if you expect to need one.

Some custodians impose a settlement hold before allowing a conversion, so ask before you open an account if a backdoor Roth is likely. See backdoor Roth IRA for the mechanics, and best Roth IRA accounts for the actual comparison.

Frequently asked questions about Roth and traditional IRAs

Can I roll a Roth IRA back into a traditional IRA?

No, moving money from a Roth IRA back into a traditional IRA is not permitted; conversions run one way only. You can convert a traditional IRA to a Roth at any time and in any amount, and since 2018 that conversion cannot be undone.

Do I have to pick the same account every year?

No, the choice is made fresh each year, and nothing commits you to repeating it. Your income, your tax bracket, and whether you are covered by a workplace plan can all change, and the answer can change right along with them. Many people end up holding both accounts for exactly this reason.

What is the difference between a Roth IRA and a Roth 401(k)?

A Roth 401(k) and a Roth IRA differ mainly in who controls the account and how much you can contribute. A Roth 401(k) is an employer plan with a much higher limit and no income ceiling, but a menu your employer chooses. A Roth IRA is yours, holds almost anything, and caps at $7,500.

Can I switch a traditional IRA to a Roth later?

Yes, converting a traditional IRA to a Roth is allowed at any age, in any amount, with no income limit. What you cannot do is reverse it once it is done. The tax lands as ordinary income in the year you convert, which makes the timing a separate decision from this one.

Does the choice change if I am self-employed?

No, the Roth versus traditional logic is identical for self-employed savers, but the accounts available to you are not. A solo 401(k) or SEP IRA usually allows far larger contributions than either IRA, and is generally worth working out before this $7,500 decision.

Nicolas Straut

Personal finance writer, former Forbes contributor and This Week in Fintech writer

Tweed provides educational estimates, not financial advice. Nicolas Straut is not a financial advisor. Break-even figures on this page are illustrative, computed from the stated assumptions, and depend on a future tax rate nobody can know in advance. Confirm your situation with a qualified professional.