Roth vs Traditional IRA Comparison
This tool compares Roth and Traditional IRA outcomes using your assumptions: separate annual contributions to each account type, employer match (applied to Traditional), current balances, current and future tax rates, and expected investment returns. It projects future balances and computes after-tax retirement values to help you evaluate which account type may deliver higher after-tax wealth.
Results are scenario-driven: change assumptions to explore sensitivity. The calculator does not provide tax advice; always verify with a tax professional for your situation.
Governance
Record 71fa86919508 • Reviewed by Fidamen Standards Committee
Projects future balances for Roth and Traditional accounts given separate contribution amounts, employer match to Traditional, current balances, tax rates, and expected return. Shows after-tax retirement values to help decide which account type gives higher after-tax wealth.
Inputs
Results
Projected Traditional balance
$628,748.03
After-tax Traditional withdrawals
$490,423.47
Projected Roth balance
$0.00
After-tax Roth withdrawals
$0.00
After-tax difference (Roth − Traditional)
-$490,423.47
| Output | Value | Unit |
|---|---|---|
| Projected Traditional balance | $628,748.03 | USD |
| After-tax Traditional withdrawals | $490,423.47 | USD |
| Projected Roth balance | $0.00 | USD |
| After-tax Roth withdrawals | $0.00 | USD |
| After-tax difference (Roth − Traditional) | -$490,423.47 | USD |
Visualization
Methodology
We model future balances using standard future value formulas: existing balances compound at the expected annual return and each year’s contribution compounds using the future value of an ordinary annuity. Employer match is treated as an additional pre-tax contribution into the Traditional account.
For Roth contributions we model them as made with post-tax dollars (employee pays income tax today), and Roth qualified distributions are assumed tax-free in retirement. For Traditional we assume contributions are pre-tax and withdrawals in retirement are taxed at the expected retirement marginal rate.
Conversion (backdoor) assessment estimates the immediate tax due at the current marginal rate on the converted pre-tax principal, then projects the converted principal's future value tax-free. The comparison includes a scenario that projects the after-tax value if funds remain in Traditional and are taxed upon withdrawal.
Key takeaways
Use separate contribution fields for Roth and Traditional to model mixed strategies. Employer match is applied to Traditional contributions by default.
Run multiple scenarios for marginal tax rates today and in retirement to understand sensitivity. The calculator provides a deterministic, assumptions-based comparison — not personalized tax or investment advice.
F.A.Q.
Does the tool account for employer match rules or non-elective employer contributions?
Employer match is modeled as an additional annual pre-tax contribution to the Traditional account proportional to the specified match percentage and your Traditional employee contribution. Specific employer plan rules and vesting are not modeled; adjust inputs if your employer match is different.
How should I choose tax rates to enter?
Use your best estimate for your current marginal rate and the rate you expect in retirement. The calculator compares after-tax results under those assumptions. Because future tax policy is uncertain, run multiple scenarios (higher and lower retirement tax rates).
Are required minimum distributions (RMDs) or early withdrawal penalties included?
This tool does not model RMD timing, penalties, or state taxes. It focuses on aggregate after-tax value at the chosen retirement age. For RMDs, age-based rules, or early withdrawal penalties, consult tax guidance and run adjusted scenarios.
How accurate are the projections?
Projections use deterministic mathematical formulas and depend entirely on your inputs. They do not model market volatility, sequence-of-returns risk, or tax-law changes. See the accuracy and standards caveats below.
Sources & citations
- IRS — Traditional and Roth IRAs (rules, limits, and distributions) — https://www.irs.gov/retirement-plans/traditional-and-roth-iras
- NIST — National Institute of Standards and Technology — https://www.nist.gov
- ISO — International Organization for Standardization — https://www.iso.org
- IEEE — Institute of Electrical and Electronics Engineers — https://www.ieee.org
- OSHA — Occupational Safety and Health Administration — https://www.osha.gov
- IRS Publication 590-B — Distributions from Individual Retirement Arrangements — https://www.irs.gov/publications/p590b
- IRS Required Minimum Distribution Worksheets — https://www.irs.gov/retirement-plans/plan-participant-employee/required-minimum-distribution-worksheets
- Social Security Administration — Retirement Benefits — https://www.ssa.gov/benefits/retirement/
Further resources
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: 71fa86919508What changed (latest)
v1.0.0 • 2025-11-17 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
What changed (latest)
v1.0.0 • 2025-11-17 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Engine
v1.0.0
Data
Baseline (no external datasets)
Content
v1.0.0
UI
v1.0.0
Governance
Last updated: Nov 17, 2025
Reviewed by: Fidamen Standards Committee (Review board)
Credentials: Internal QA
Risk level: low
Reviewer profile (entity)
Fidamen Standards Committee
Review board
Internal QA
Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person
Semantic versioning
- MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
- MINOR: New features or fields that do not change existing outputs for the same inputs.
- PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.
Review protocol
- Verify formulas and unit definitions against primary standards or datasets.
- Run golden-case regression suite and edge-case suite.
- Record reviewer sign-off with credentials and scope.
- Document assumptions, limitations, and jurisdiction applicability.
Assumptions & limitations
- Uses exact unit definitions from the Fidamen conversion library.
- Internal calculations use double precision; display rounding follows the unit's configured decimal places.
- Not a substitute for calibrated instruments in regulated contexts.
- Jurisdiction-specific rules may require official guidance.
Change log
v1.0.0 • 2025-11-17 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 69cb8eb7a9b1
- https://www.ieee.org
- https://www.irs.gov/publications/p590b
- https://www.irs.gov/retirement-plans/plan-participant-employee/required-minimum-distribution-worksheets
- https://www.irs.gov/retirement-plans/traditional-and-roth-iras
- https://www.iso.org
- https://www.nist.gov
- https://www.osha.gov
- https://www.ssa.gov/benefits/retirement/