Decision
Roth or traditional — which should I use?
At the same tax rate at both ends, a Roth and a traditional account produce mathematically identical results — most comparisons never do that arithmetic. The real Roth advantage is that the contribution limit applies to the nominal amount, so a full contribution shelters more money.
How to think about it
Contribute $7,500 a year for 30 years at 7% and either account reaches about $762,500. Withdraw the traditional at a 22% rate and you keep about $594,700.
Now match the true cost. The $7,500 traditional contribution only costs $5,850 out of pocket, because the deduction refunds $1,650. Put that same $5,850 into a Roth and it grows to about $594,700 — tax-free, and exactly the same figure. At equal rates the accounts are indistinguishable.
That identity is what makes the real difference visible. The limit is on the nominal contribution, so a full $7,500 into a Roth shelters the entire $762,500 rather than $594,700 — about $167,700 more, for $1,650 a year of extra out-of-pocket cost. For anyone able to contribute the maximum, the Roth is effectively the larger account.
Work through these, in this order
- Which wins at my actual tax rates?Applies your rate today and your expected rate in retirement rather than a rule of thumb. If the two are close, the answer is close — and that is useful information, not a failure of the tool.Open the Roth vs Traditional 401(k) Calculator
- What does the Roth side look like on its own?No tax term appears at the end, because qualified withdrawals are untaxed. Contributions — not earnings — can also be withdrawn at any time, which makes it a genuine second line of defence.Open the Roth IRA Calculator
- And the traditional side?Shows the deduction today alongside the estimated tax on the way out, which is the trade being made. It also carries required minimum distributions from 73 that the Roth does not.Open the Traditional IRA Calculator
- Am I allowed to contribute directly?Direct Roth contributions phase out at higher incomes. The limit applies to contributions, not conversions, which is why the next step exists.Open the Roth IRA Contribution Limit Calculator
- If I earn too much, what does the workaround cost?The pro-rata rule taxes a conversion in proportion to all existing pre-tax IRA balances — $7,500 added to an existing $67,500 makes 90% of the conversion taxable. Price it before converting, not after.Open the Backdoor Roth Calculator
What the numbers together tell you
Choose traditional if your rate is genuinely lower later — peak earners in high-tax states expecting to retire on less, in a cheaper state, are the clearest case. Choose Roth if your rate is likely to rise, if you are early in your career, or if you can contribute the full limit either way.
If you cannot tell, splitting is a hedge rather than indecision: it guarantees you are partly right whichever way rates move, and holding both gives you control over your taxable income in retirement.
Low-income years — a career break, graduate school, the window between retiring and claiming Social Security — are the conversion opportunity, and one of the few genuinely free lunches in tax planning.
Read more about this
Traditional vs. Roth IRA: Which Retirement Account Wins?
A traditional IRA deducts taxes now and taxes withdrawals later; a Roth is funded after-tax but grows tax-free. The choice comes down to one question: will your tax rate be higher now or in retirement? Here's how to decide.
How a 401(k) Match Works (Don't Leave Free Money)
An employer 401(k) match is free money — your company adds to your retirement based on what you contribute. Here's how match formulas work, why they come first, and how to capture the full amount.
Frequently asked questions
Is a Roth always better for young savers?
Usually, because a low current rate is likely to rise and decades of growth come out untaxed. It is not automatic — someone in a high bracket early who expects to retire on much less is the exception.
Where does the employer match go?
Traditionally to the pre-tax side regardless of your own election. Recent rules let plans offer a Roth match, which counts as taxable income in the year received, but most plans still default to pre-tax. Your statement will say.
Related decisions
How much do I need to retire?
Turn the spending you want into a number, check whether your current saving reaches it, and see what Social Security and a later claiming age take off the total.
Am I saving enough?
Check your savings rate, size your emergency fund on lean spending rather than income, and see whether the total is on track for what you want later.
What will I actually take home?
Turn a salary offer into the number that reaches your account, then check what a raise, a contribution change or self-employment does to it.
Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.