What this calculator does
It projects your 401(k) balance year by year from now until retirement. Each year, your salary grows by an assumed raise, you defer a percentage of it up to the IRS limit for your age, your employer contributes under whatever match or non-elective formula you select, and the running balance grows at your assumed rate of return. The result is a single projected balance at retirement, shown both in actual dollars and in today's purchasing power.
What each input means
- Current age and retirement age. These set how many years the projection runs. If retirement age is not later than current age, there is nothing to project and the calculator says so rather than showing a zero balance as if it were a real result.
- Current salary. Your gross annual salary today. It grows each projected year by the annual raise percentage.
- Current 401(k) balance. What is already in the account. It carries forward and keeps compounding alongside new contributions.
- Your deferral. The percentage of salary you contribute yourself, before any employer money.
- Expected annual return. The growth rate applied to the balance each year. There is no way to know this in advance; try a few values to see how sensitive the result is.
- Annual raise and assumed inflation. The raise compounds your salary upward each year. Inflation is used only to convert the final nominal balance into today's dollars; it does not change the nominal projection itself.
- Employer match. Pick a preset formula, including the two safe harbor match designs, or choose Custom to enter your own single-tier match.
- Non-elective contribution. Money your employer pays in regardless of what you defer. Separate from the match, and stacks on top of it if your plan happens to offer both.
Worked example
A 30-year-old earning $80,000, with $20,000 already saved, deferring 6% of salary into a plan that matches 50% of the first 6% deferred, assuming a 7% annual return, a 3% annual raise and 2.5% inflation, retiring at 65:
- Final balance at 65: roughly $1,727,891.
- The same balance in today's dollars: roughly $728,083.
- Total of your own contributions over 35 years: roughly $290,218.
- Total employer contributions: roughly $145,109.
- Investment growth: roughly $1,272,564, the largest single piece of the total.
A high earner shows how the IRS limit binds: a 45-year-old on a $350,000 salary deferring 10% is asking to contribute $35,000 in the first year, above the 2026 elective deferral limit. The calculator caps that year's deferral at the limit and marks the year as limited, rather than silently contributing more than the law allows.
How the IRS limits are applied
Your deferral is capped at the elective deferral limit for your age in each projected year: the standard limit under 50, a higher limit from 50 through 59, an even higher SECURE 2.0 catch-up limit from 60 through 63, and back to the standard catch-up at 64 and beyond. Separately, your deferral and your employer's contribution together are capped by the section 415(c) annual additions limit; if that combined cap binds, the employer share is trimmed first, since your own deferral is money you chose to defer. This calculator uses the 2026 figures for all of these limits.
Frequently asked questions
Why does the projection show two final numbers?
The larger figure is the nominal balance: the actual number of dollars in the account on the day you retire. The smaller figure restates that same balance in today's purchasing power, using your assumed inflation rate. A dollar in 35 years buys less than a dollar today, so the second figure is the more honest one for comparing against what you could buy with your money now.
What is the difference between a preset match and a custom match?
The presets cover the employer match formulas that are actually common in practice, including the two safe harbor designs. Custom lets you model a single-tier match your own plan uses that is not in the list, such as "50% of the first 6% deferred". It only supports one tier; a two-tier formula like the safe harbor basic match needs that preset.
What is the non-elective contribution field for?
It is separate from the match, because it is paid whether or not you defer anything. If your plan uses the safe harbor non-elective design, select it from the match dropdown and the field locks to 3% of pay, which is what that design requires. Otherwise you can enter any non-elective percentage your plan offers on top of, or instead of, a match.
What happens once I turn 50 or reach 60 through 63?
The IRS lets you defer more than the standard limit from age 50, and more again from 60 through 63 under a SECURE 2.0 catch-up provision, before dropping back to the standard catch-up at 64. This calculator applies the correct limit for the age in each projected year automatically; you do not need to enter it.
Why did my contribution get capped in some years?
Two IRS limits can bind. Your own deferral cannot exceed the elective deferral limit for your age (higher from 50, higher again from 60 to 63). Separately, section 415(c) caps your contribution and your employer's combined; if that combined limit binds, this calculator trims the employer share first, since your own deferral is yours to make. When either limit changes what you actually contributed, the calculator says so and lists the ages affected.
Is this financial advice?
No. This is a projection based on the assumptions you enter, not a guarantee or a recommendation. Actual market returns, salary growth and IRS limits will all differ from any fixed assumption over a multi-decade projection.
This calculator is a planning estimate, not financial or tax advice. It does not model vesting schedules, plan-specific eligibility rules, or fees.