401k Calculator

2026 401(k) contribution limits and matching

The IRS sets annual 401(k) contribution limits. For 2026, the employee elective deferral limit is $24,500 for workers under 50. Employees age 50 or older can add an $8,000 catch-up contribution, and employees who turn 60, 61, 62 or 63 during the calendar year may have a higher $11,250 catch-up if the plan allows it. Those limits cover your pre-tax and Roth deferrals combined.

The calculator applies those 2026 limits as a current-law guard in every projected year. It applies the $360,000 compensation cap to the employer-match formula; it does not stop employee elective deferrals when pay passes that cap unless the employee reaches the separate deferral limit. It does not forecast future IRS cost-of-living increases, so a decades-long projection may be conservative if future limits rise.

It models one plan using your elective deferral and the entered employer match. Deferrals to other plans can share the personal deferral limit, while after-tax employee contributions, employer nonelective or profit-sharing contributions and forfeiture allocations can use part of the annual-additions limit. Plan terms and nondiscrimination rules can impose lower limits; adjust the inputs or ask the plan administrator when those items apply.

The projection is in gross US dollars before fees and taxes. It divides each year’s employee contribution and estimated employer match into 12 equal month-end deposits, converts the entered effective annual return to a monthly-equivalent rate and compounds monthly. Salary growth is applied once after each projection year. The annual table includes every year, not selected samples.

What match formula the calculator can model

The calculator models one flat match tier: one employer percentage applied to your actual contribution, up to one percentage of eligible salary. For example, “100% on contributions up to 5% of pay” can be entered directly. A formula such as “100% on the first 3%, then 50% on the next 2%” has two tiers and cannot be reproduced exactly with these two fields. At a contribution of at least 5%, an 80% match up to 5% approximates its 4%-of-pay maximum, but it will not match the plan at lower contribution rates. Use the result as an estimate or calculate each tier separately.

If you plan to hit the IRS maximum before December, check whether your employer provides a true-up match. Some plans match each paycheck only; without a true-up, front-loading too much early in the year can accidentally forfeit matching dollars later.

Why growth can become large in a long positive-return projection

Compounding is exponential when returns are positive. At a steady 7% annual return, a balance with no further deposits or withdrawals would double roughly every 10.3 years before fees and taxes (rule-of-72 estimate: 72 / 7 = 10.3). Longer horizons give earlier deposits more time to compound, while shorter horizons generally leave less time for growth. This is a mathematical scenario, not a return forecast; actual returns vary and can be negative.

Traditional vs. Roth 401(k)

This calculator projects the gross balance. Whether you pay income tax on withdrawals (traditional) or contribute after-tax and later take qualified tax-free Roth distributions changes the spendable amount but not this projection. For 2026, a participant whose 2025 FICA wages from the employer sponsoring the plan exceeded $150,000 generally must designate catch-up contributions as Roth. Plan features and exceptions matter; if an affected plan does not permit Roth contributions, catch-up contributions may be unavailable. Check the plan document or administrator.