How it works
The calculator projects your account balance using:
FV = current × (1+r)^n + (annual contributions) × growth factor
Where annual contributions = (your contribution % + employer match %) × annual salary, capped at IRS limits.
For 2026: the elective deferral limit is $23,500 ($31,000 if 50+). Total contributions including employer match are capped at $70,000.
What to know
- Always contribute up to the match. A 100% match on 5% of salary is a 100% return on day one. Anything less is leaving free money.
- Roth 401(k) vs traditional. Roth contributions are after-tax (tax-free in retirement). Traditional is pre-tax (taxed at withdrawal). Most early-career people benefit more from Roth.
- Vesting matters. Employer match may vest over 3 to 6 years. Leaving early forfeits unvested portion.
- Fees eat returns. Many 401(k) plans have funds with 1%+ expense ratios. Picking the lowest-cost index option (often <0.10%) preserves tens of thousands over a career.
Worked example
Salary $75,000, you contribute 10%, employer matches 4%, 7% return, 35 years:
- Annual contribution: $10,500 (your $7,500 + employer $3,000)
- Total contributed over 35 years: $367,500
- Final balance: ~$1.5 million
Three-quarters of the result comes from compounding, not your contributions.
Frequently asked questions
How much should I contribute to my 401(k)?
At minimum, contribute up to your full employer match. From there, aim for 15% of gross income across all retirement accounts. Maxing the 401(k) is a good goal once you are out of high-interest debt.
What is the 2026 contribution limit?
$23,500 for elective deferrals if under 50. $31,000 if 50 or older (includes the $7,500 catch-up). Total contributions including employer match cannot exceed $70,000.
Should I do Roth 401(k) or traditional 401(k)?
If you expect to be in a higher tax bracket in retirement than now, Roth wins. If lower, traditional wins. For early-career workers, Roth is usually the better bet.
What happens if I leave my job?
Your contributions are always yours. Employer match vests on a schedule (often 3 to 6 years). On leaving, you can roll the balance to an IRA, your new employer's plan, or leave it (if balance > $7,000).