Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Better option
Roth wins
Roth after-tax value
$661,226
Traditional after-tax value
$566,156
Difference
$95,070
Pre-tax balance
$661,226
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter annual contribution ($).
- 2Enter years invested.
- 3Enter annual return (%).
- 4Enter tax rate today (%).
- 5Enter tax rate in retirement (%).
- 6Read your better option on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Traditional gives you the deduction now and taxes withdrawals later. Roth taxes you now and pays out clean. Which wins depends on your tax rate then vs now.
Worked example
Using the values the calculator loads with:
Inputs
- Annual contribution: 7000 $
- Years invested: 30
- Annual return: 7 %
- Tax rate today: 24 %
- Tax rate in retirement: 22 %
Results
- Better option: Roth wins
- Roth after-tax value: $661,226
- Traditional after-tax value: $566,156
- Difference: $95,070
- Pre-tax balance: $661,226
What each field means
Inputs
- Annual contribution ($)
- The annual contribution used in the calculation, measured in $. Starts at 7000 $ so you have a working example on load.
- Years invested
- The years invested used in the calculation. Starts at 30 so you have a working example on load. Accepted range: 1–60.
- Annual return (%)
- The annual return used in the calculation, measured in %. Starts at 7 % so you have a working example on load. Accepted range: 0–20 %.
- Tax rate today (%)
- The tax rate today used in the calculation, measured in %. Starts at 24 % so you have a working example on load. Accepted range: 0–60 %.
- Tax rate in retirement (%)
- The tax rate in retirement used in the calculation, measured in %. Starts at 22 % so you have a working example on load. Accepted range: 0–60 %.
Results
- Better option
- Returned as a plain value and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Roth after-tax value
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Traditional after-tax value
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Difference
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Pre-tax balance
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the roth vs traditional ira calculator work?
Traditional gives you the deduction now and taxes withdrawals later. Roth taxes you now and pays out clean. Which wins depends on your tax rate then vs now. The underlying maths is: Roth after-tax = FV. Traditional after-tax = FV × (1 − retirement rate)
What do I need to enter?
5 values: annual contribution, years invested, annual return, tax rate today, and tax rate in retirement. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the better option result mean?
It is returned as a plain value and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Roth vs Traditional IRA Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/roth-vs-traditional
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/roth-vs-traditional" target="_blank" rel="noopener">Roth vs Traditional IRA Calculator — RevenueLab</a> (2026).</p>
Source: [Roth vs Traditional IRA Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/roth-vs-traditional) (2026).