401(k) Calculator
Model employee deferrals, employer matching, age-based catch-up contributions, and investment growth separately. The projection starts with 2026 federal limits, lets future limits grow only by an explicit assumption, and deposits contributions monthly.
How to use the 401(k) Calculator
Enter current balance, salary, employee rate, age, employer match formula, prior-year FICA wages from this sponsor, plan Roth catch-up availability, salary and future-limit growth, annual return, and years.
Review current IRS limits, catch-up eligibility, plan compensation definition, vesting, match cap, investment risk, tax treatment, and fee disclosures.
Read projected balance, regular and age-based employee deferrals, required Roth catch-up bucket, unavailable Roth catch-up amount, employer contributions, and investment growth.
Formula
Regular deferral is capped at the modeled $24,500 limit; eligible age catch-up is added separately. Employer match follows the entered rate and salary cap, regular additions observe the modeled $72,000 limit, and cash flows enter monthly.
Example
On $60,000 salary, a 6% deferral is $3,600 and a 50% match through 6% adds $1,800 before annual-limit and eligibility checks; both are deposited across 12 months.
Assumptions and limitations
- For 2026, prior-year FICA wages from this plan sponsor above $150,000 require age-based catch-up contributions to use Roth treatment when the plan offers catch-up. The model excludes rather than mislabels the catch-up when Roth catch-up is marked unavailable.
- 401(k) Calculator treats the entered values as estimates and does not infer missing project, account, or personal details.
- Calculations retain working precision except where the cited method requires an intermediate rounding step; displayed values are then formatted separately. Source rules and dated rates must be rechecked when they change.
Sources
- Internal Revenue Service: 401(k) Plan Overview401(k) contributions, elective deferrals, and plan concepts. Reviewed 2026-08-14.
- Internal Revenue Service: Retirement Topics: Catch-Up Contributions2026 age-based catch-up limits and the prior-year wage test for required Roth catch-up treatment. Reviewed 2026-08-14.
- U.S. Securities and Exchange Commission: Compound Interest CalculatorCompound-growth inputs and future-value concepts. Reviewed 2026-08-14.
- Internal Revenue Service: 401(k) and profit-sharing plan contribution limitsOfficial formula, rate, or program guidance used by this calculator. Reviewed 2026-08-14.
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Frequently asked questions
How does the 401(k) Calculator work?
Regular deferral is capped at the modeled $24,500 limit; eligible age catch-up is added separately. Employer match follows the entered rate and salary cap, regular additions observe the modeled $72,000 limit, and cash flows enter monthly.
What information should I enter in the 401(k) Calculator?
Enter current balance, salary, employee rate, age, employer match formula, prior-year FICA wages from this sponsor, plan Roth catch-up availability, salary and future-limit growth, annual return, and years, then verify current IRS limits, catch-up eligibility, plan compensation definition, vesting, match cap, investment risk, tax treatment, and fee disclosures.
What should I verify before using this 401(k) Calculator result?
For 2026, prior-year FICA wages from this plan sponsor above $150,000 require age-based catch-up contributions to use Roth treatment when the plan offers catch-up. The model excludes rather than mislabels the catch-up when Roth catch-up is marked unavailable.
Reviewed 2026-08-14 · 2026-monthly-retirement-projection-v4 · content-2026-08-14 · Trusty Calculator Editorial Team