401(k) Calculator 2026 โ Roth, Traditional & Employer Match
Compare Roth vs Traditional, model your real employer match formula, and project year-by-year retirement growth.
401(k) Details
Contributions reduce taxable income now. Withdrawals taxed at retirement.
Effective employer contribution: 3.00% of salary
Estimated Balance at Age 65
$2,023,304
In 35 years ยท Pre-tax
After-tax retirement balance
$1,780,507
Assumes 12% effective tax on withdrawals
Retirement Savings Breakdown
* Estimate for educational purposes only. Does not account for inflation or IRS contribution limit changes beyond the 2026 employee deferral cap of $24,000.
Roth vs Traditional 401(k)
The single biggest decision when setting up your 401(k) is whether to use the Traditional or Roth bucket โ and the answer depends on your current vs future tax bracket.
Traditional 401(k)
- Pre-tax contributions reduce taxable income today
- Investments grow tax-deferred
- Withdrawals in retirement taxed as ordinary income
- Best if your current tax bracket > retirement tax bracket
Roth 401(k)
- After-tax contributions (no immediate tax break)
- Investments grow tax-free
- Qualified withdrawals in retirement are tax-free
- Best for younger workers or if you expect higher future taxes
Use the Account Type toggle above to compare both outcomes side by side. The calculator shows your nominal balance, the after-tax balance (Traditional), and lifetime tax savings.
How the Employer Match Really Works
Most 401(k) calculators (including the popular SmartAsset version) only let you set a flat employer match percentage. Real plans use a formula: a match percentage applied to your contribution, up to a salary cap.
| Formula | You contribute | Employer adds | Total to 401(k) |
|---|---|---|---|
| 100% up to 3% | 3% of salary | 3% of salary | 6% of salary |
| 50% up to 6% | 6% of salary | 3% of salary | 9% of salary |
| 100% up to 6% | 6% of salary | 6% of salary | 12% of salary |
Rule of thumb:always contribute at least up to the match cap. If your employer offers โ100% up to 6%โ and you only contribute 4%, you are leaving 2% of salary in free money on the table every year.
Vesting Schedules โ When the Match Becomes Yours
The employer match isn't fully yours the day it lands in your account. Vesting is the schedule by which those employer contributions transfer to your ownership. Your own contributions are always 100% vested immediately.
Cliff Vesting
You get 0% of the employer match until you hit a threshold (e.g., 3 years), then 100% all at once. Leave before the cliff โ you forfeit everything matched.
Graded Vesting
You vest in increments โ commonly 20% per year over 5 years, or 25% per year over 4. You keep a portion of the match if you leave early.
Safe Harbor 401(k) plans (which include โ100% up to 3%โ or โ100% up to 4%โ match formulas) are required by IRS rules to be 100% immediately vested โ a major perk of those plans.
How SmartCalcs Compares to Other 401(k) Calculators
Popular tools like SmartAsset and NerdWallet offer 401(k) projections, but most stop at flat-percentage assumptions. Here's how this calculator differs:
| Feature | SmartCalcs | Typical free tools |
|---|---|---|
| Roth vs Traditional side-by-side | โ | Partial |
| Real match formula (% up to X%) | โ | Flat % only |
| Year-by-year breakdown | โ | Sometimes |
| After-tax retirement balance | โ | Rare |
| No signup / email required | โ | Varies |
Frequently Asked Questions
Traditional 401(k) contributions are pre-tax, so you save on taxes now but pay income tax when you withdraw in retirement. Roth 401(k) contributions are after-tax, but qualified withdrawals are completely tax-free. Roth is generally better if you expect to be in a higher tax bracket in retirement than you are today, or if you have decades of compounding ahead. Traditional is better if your current marginal rate is high and you expect a lower rate at retirement.
An employer match means your company contributes to your 401(k) based on how much you contribute. The most common formulas are "100% match up to 3% of salary" (a Safe Harbor design) and "50% match up to 6% of salary." For example, if you earn $80,000 and your employer matches 100% up to 3%, contributing at least 3% ($2,400) earns you another $2,400 from your employer โ essentially free money.
Vesting refers to how much of your employer's match you actually own. Common schedules are cliff vesting (e.g., 0% for 2 years, then 100% at year 3) and graded vesting (e.g., 20% per year over 5 years). Your own contributions are always 100% vested immediately. If you leave the company before fully vesting, you may forfeit some or all of the employer match.
Financial experts recommend saving 10% to 15% of your pre-tax income for retirement. At a minimum, contribute enough to capture the full employer match โ anything less leaves free money on the table. The 2026 IRS employee deferral limit is approximately $24,000 (with an additional $7,500 catch-up if you are 50 or older).
The S&P 500 has historically returned about 10% nominally (around 7% after inflation) over long periods. For retirement planning, 6% to 7% is a conservative real-return assumption. Use a lower number (4-5%) if you have a bond-heavy portfolio or want to plan for a more pessimistic outcome.
SmartAsset offers a basic 401(k) calculator with limited employer match modeling. This SmartCalcs 401(k) calculator adds: (1) full Roth vs Traditional comparison with after-tax retirement balance, (2) realistic employer match formulas with presets (100% up to 3%, 50% up to 6%, custom), (3) year-by-year growth breakdown, and (4) a vesting schedule explainer โ all free with no signup required.