Interactive Tool
401k vs Roth IRA Calculator
See your projected retirement balance under three scenarios. This calculator factors in employer match, tax brackets, and compound growth to show you exactly how much each approach is worth.
Updated April 2026 with current IRS limits
Your Details
50 = 50 cents per dollar
6 = matches up to 6% of salary
Average annual salary increase
Federal marginal rate now
Expected rate at withdrawal
7% is typical long-run average
A: 401k Only
$3.68M
after 15% tax
B: Roth IRA Only
$1.14M
completely tax-free
C: Optimal Order
$4.82M
match + Roth + 401k
After-Tax Retirement Balance Comparison
Growth Over Time (After-Tax Value)
| Year | 401k Only | Roth Only | Optimal |
|---|---|---|---|
| Year 5 | $140,588 | $46,150 | $186,738 |
| Year 10 | $339,753 | $110,877 | $450,630 |
| Year 15 | $621,389 | $201,660 | $823,050 |
| Year 20 | $1.02M | $328,989 | $1.35M |
| Year 25 | $1.62M | $514,342 | $2.14M |
| Year 30 | $2.47M | $774,310 | $3.24M |
| Year 35 | $3.68M | $1.14M | $4.82M |
Total match received
$136,040
Free employer contributions over 35 years
Tax-free Roth portion
$1.14M
Withdrawable without any tax
Lifetime tax savings
$217,910
Deductions from 401k contributions
The key insight
The optimal order (Scenario C) produces $4.82M in after-tax retirement wealth, which is $3.68M more than the Roth-only approach. The employer match and the higher 401k contribution limit make up the difference. Both accounts together are better than either one alone.
Common Scenarios
Not sure what to enter? These represent typical situations at different career stages.
Entry-level (age 25)
$55,000 salary, 50% match up to 6%, 22% bracket, 40 years to grow
Mid-career (age 35)
$95,000 salary, 100% match up to 3%, 24% bracket, 30 years to grow
Senior (age 45)
$140,000 salary, 50% match up to 4%, 32% bracket, 20 years to grow
How to Read Your Results
What the scenarios mean
- Scenario A (401k Only): You max out your 401k at $24,500 per year with employer match. All growth is tax-deferred. Withdrawals are taxed at your retirement bracket.
- Scenario B (Roth IRA Only): You contribute $7,500 per year to a Roth IRA with no employer match. All growth and withdrawals are completely tax-free.
- Scenario C (Optimal Order): You contribute to the 401k up to the match, max the Roth IRA, then go back to the 401k. This captures the match AND gets Roth tax-free growth.
Assumptions built in
- Constant contributions: The calculator assumes you contribute the same amount each year. In reality, contributions often increase with salary growth.
- Constant return: The default 7% reflects the long-run average of a diversified stock portfolio after inflation. Actual returns vary year to year.
- Tax bracket stays constant: Your retirement tax bracket may differ. If you expect a lower bracket in retirement, the 401k becomes relatively more attractive.
- 2026 limits used: Contribution limits increase periodically. Future limit increases would improve all scenarios.