401k Contribution Calculator: Limits, Employer Match, and Room
Your 401k is one of the most powerful retirement savings tools available, combining tax advantages with the potential for employer matching contributions that are essentially free compensation. This calculator helps you understand exactly how much you and your employer are contributing annually, whether you are on track to hit the IRS limits, and how much room remains. Enter your annual salary, the percentage of your salary you elect to contribute, your employer's matching formula (the match rate and the salary percentage they match up to), and your age. The calculator applies the 2025 IRS limits: $23,500 for employee contributions, with an additional $7,500 catch-up for those aged 50 and older (and $11,250 for those aged 60 to 63 under SECURE 2.0), and a combined limit of $70,000. It shows your employee contribution, employer match, total, and the remaining contribution room under each cap. The limits are user-editable so you can update them when the IRS announces new figures each October. Always verify current limits against IRS Notice 2024-80 or the IRS website before making contribution elections.
Formulas
Employee contribution = salary x (contrib % / 100)
Employee contribution is capped at employee limit (plus catch-up if age is 50 or older).
Employer match = salary x (min(contrib %, match-up-to %) / 100) x (match rate / 100)
Total contribution = employee contribution + employer match
Catch-up eligible: age 50 or older ($7,500; or $11,250 for ages 60-63 under SECURE 2.0 Act)
Employee room = max(0, employee limit + catch-up (if eligible) - employee contribution)
Total room = max(0, combined limit - total contribution)
Note: the $11,250 special catch-up for ages 60-63 (SECURE 2.0 Act) is not yet reflected in the default limit field; update the catch-up input to $11,250 if you are in that age range.
How to use this calculator
- Enter your gross annual salary and the percentage you elect to defer to your 401k.
- Enter your employer's match rate (e.g. 100 for dollar-for-dollar) and the maximum percentage of salary they will match (e.g. 6 for up to 6% of salary).
- Enter your age. If you are 50 or older the catch-up contribution is added to your employee cap.
- The 2025 IRS limits are pre-filled. Update them each October when the IRS announces the following year's figures.
- Read your employee contribution, employer match, and remaining room from the output panel.
- If you are aged 60 to 63, update the catch-up field to $11,250 to reflect the higher SECURE 2.0 limit.
Frequently asked questions
What are the 2025 401k contribution limits?
For 2025, the IRS employee elective deferral limit is $23,500. Employees aged 50 and older may make catch-up contributions of an additional $7,500, for a total of $31,000. Employees aged 60 to 63 may make a special higher catch-up of $11,250 under the SECURE 2.0 Act, for a total of $34,750. The combined limit (employee plus employer contributions) is $70,000, or $77,500 with catch-up. These limits are published in IRS Notice 2024-80.
Does my employer match count toward my contribution limit?
No. The $23,500 employee limit applies only to your elective deferrals. Employer matching contributions are additional and count only toward the combined $70,000 total limit (not the $23,500 employee limit). So if you contribute $23,500 and your employer adds $10,000, your total is $33,500, which is well under the combined cap.
What is a common employer match formula?
The most common structure is a 50% or 100% match on contributions up to a percentage of salary, often 3% to 6%. For example, a "50% match up to 6% of salary" means if you earn $80,000 and contribute 6% ($4,800), your employer adds 3% ($2,400). Always contribute at least enough to get the full match as it is effectively part of your compensation.
Are 401k contributions tax-deductible?
Traditional (pre-tax) 401k contributions reduce your taxable income in the year they are made, deferring tax until withdrawal in retirement. Roth 401k contributions are made with after-tax dollars and are not deductible, but qualified withdrawals in retirement are tax-free. The contribution limit is the same for both.
What happens if I over-contribute to my 401k?
Excess contributions must be returned to you (with attributed earnings) by April 15 of the following year. If not corrected in time, they may be taxed twice. Your plan administrator should catch over-contributions but track your total against the published limits, especially if you change jobs mid-year.
Official sources
- IRS: 401k contribution limits: irs.gov/retirement-plans/plan-participant-employee/retirement-topics-401k-and-profit-sharing-plan-contribution-limits.
- IRS Notice 2024-80 (2025 limits): irs.gov/pub/irs-drop/n-24-80.pdf.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.