How it works
What this calculation includes
A 401(k) projection adds the deferral and employer match for each year to a balance that grows at an assumed return. This calculator steps one month at a time. The balance grows by one-twelfth of the nominal annual return, and one-twelfth of that year of deferral and match is added.
The deferral is your salary times the deferral percent. When that amount is above the 2026 IRS employee limit (and catch-up when age allows), the deferral is reduced to the limit.
The employer match is shown separately so that deferrals, match and growth can be compared. Vesting schedules and plan fees are not included.
401(k) balance growth
In words Each month the balance grows at the monthly return, then employee deferral and employer match for that month are added.
- Account balance
- Nominal annual return
- Annual employee deferral (capped when the IRS limit is known)
- Annual employer match
The deferral is reduced to the IRS employee limit for the tax year when that limit is published in the site data.
Example
- Salary: $90,000.00
- Deferral: 6%
- Match: 50% up to 6% of salary
- Starting balance: $40,000.00
- Years: 10
- Return: 7% nominal, monthly
- Each month: balance × (1 + r/12), then add (deferral + match) ÷ 12.
- Deferral is reduced to the IRS employee limit when that limit is available.
Ending balance: $197,218.70
Worked example
Using the default inputs on this page.
- Annual salary
- $80,000.00
- Annual salary growth
- 3.00%
- Your contribution
- 8.00%
- Employer match rate
- 50.00%
- Match applies up to
- 6.00%
- Current balance
- $25,000.00
- Current age
- 35
- Retirement age
- 65
- Estimated annual return
- 6.00%
Projected balance at age 65
$1,177,261
6.00% nominal return over 30 years
Questions
What is the 2026 employee deferral limit?
The elective deferral limit for 2026 is $24,500. If you are age 50 or older, a catch-up amount of $8,000 may be added. Figures come from IRS Notice 2025-67.
How does employer match work here?
The match rate is multiplied by the smaller of your deferral and the match cap percent of salary. For a 50% match up to 6% of salary on $100,000, a 6% deferral earns $3,000.
Does salary growth change later years?
Yes. The deferral percent is applied to salary in each year, and salary grows by the percent you enter at the start of each year.
What is not modeled?
Vesting schedules, plan fees, after-tax contributions, loans, and the higher catch-up that can apply at ages 60 to 63.
Sources
- IRS Notice 2025-67 (2026 retirement plan limits) Internal Revenue Service. Retrieved 2026-10-16.
- Retirement topics: 401(k) and profit-sharing plan contribution limits Internal Revenue Service. Retrieved 2026-10-12.
- Compound interest calculator U.S. Securities and Exchange Commission, Investor.gov. Retrieved 2026-10-11.