ReckonBoxWhat your 401(k) grows into
A 401(k) calculator projects your balance at retirement from your salary, your contribution, the employer match, and the return, and the match is the part worth watching. It is money you get only by contributing, so how much of it you capture changes the outcome more than most people realize.
On a $70,000 salary from age 30 to 65, contributing 6% with a 50% employer match up to 6% at a 7% return, the projected balance is about $1,345,144. Your own contributions add up to $253,941, and the employer match adds $126,970 more before it earns a cent of growth.
The match cliff, and the money left on the table
The match cliff is the minimum contribution needed to capture the full employer match, and contributing below it forfeits free money every single year. Miss it and no calculator we tore down tells you what you gave up.
Say your employer matches 50% up to 6% of salary, and you contribute 3%. On $70,000 that is $1,050 of match you forfeit in year one alone. Invested at 7% until retirement, that yearly shortfall would have grown to about $206,396. The fix costs nothing but redirecting your own contribution up to the 6% cap:
| $70,000 salary, 50% match up to 6% | Contribute 3% | Contribute 6% |
|---|---|---|
| Your contribution, year one | $2,100 | $4,200 |
| Employer match, year one | $1,050 | $2,100 |
| Match forfeited, year one | $1,050 | $0 |
Where the IRS limit bites
The IRS caps what you can contribute to a 401(k) each year, and a calculator that ignores the cap will overstate your balance. For 2026, per the IRS, the employee limit is $24,500 under age 50, $32,500 with the age-50 catch-up, and $35,750 for the SECURE 2.0 super catch-up at ages 60 to 63.
This tool caps your contribution at the limit you set and flags the years you hit it, so a 20% contribution on a high salary does not quietly assume you shoveled in more than the law allows. Combined employee and employer contributions have their own ceiling of $72,000 for 2026.
Where the numbers come from
Each year the calculator grows your salary by the raise rate, works out your contribution as a percent of that salary capped at the IRS limit, and adds the employer match. The match is the match rate applied to the lesser of what you contributed and the match cap, so contributing above the cap earns no more match. The running balance grows at your expected return, and the contributions land at year end.
The forfeited-match figure runs the same projection on the gap between your contribution and the match cap, so you see both the dollars lost this year and what they would have become. All of it assumes steady rates, which real markets and careers do not deliver.
What this does not decide for you
This projects one set of assumptions, not your retirement. It does not model taxes on withdrawal, a Roth versus traditional split, vesting schedules that can claw back an unvested match if you leave early, or the sequence of returns that makes two identical averages end very differently. A 7% average with a crash near retirement is not the same as a smooth 7%.
None of this is advice on how much to save or how to invest it. For a plan built around your own finances and tax picture, a licensed financial adviser or a CPA is the right call.
Frequently asked questions
How much will my 401(k) be worth at retirement? It depends on your salary, contribution, match, and return. On a $70,000 salary from age 30 to 65, contributing 6% with a 50% employer match up to 6%, at a 7% return, the projected balance is about $1,345,144. Of that, $126,970 is employer match before any growth, which is money you would never have without contributing.
What is the 401(k) employer match cliff? The match cliff is the minimum contribution needed to capture the full employer match, below which you forfeit free money every year. If your employer matches up to 6% of salary and you contribute only 3%, on a $70,000 salary you give up $1,050 of match in year one, which invested to retirement would have grown to about $206,396.
How does an employer 401(k) match work? An employer match adds money based on what you contribute, up to a cap stated as a percent of salary. A common formula is 50% of the first 6% you contribute, so on a $70,000 salary a full 6% contribution of $4,200 earns a $2,100 match. Contributing above the 6% cap earns no extra match, though it still grows tax-deferred.
What is the 401(k) contribution limit for 2026? For 2026, per the IRS, the employee elective-deferral limit is $24,500 under age 50, $32,500 with the age-50 catch-up, and $35,750 for the SECURE 2.0 super catch-up at ages 60 to 63. Combined employee and employer contributions are capped at $72,000. This tool caps your contribution at the limit you set and flags when you reach it.
Should I contribute more than the employer match? Contributing at least up to the match cap captures the full match, and contributing beyond it still grows tax-deferred up to the IRS limit, so the decision turns on your other goals and budget. This tool shows the balance, the match captured, and any match left on the table, so the tradeoff is visible rather than assumed.
How much of my 401(k) is free employer money? On the default projection, the employer match totals $126,970 of the contributions over 35 years, before it earns any return, against your own $253,941. Because the match compounds alongside your own money, its share of the final balance is larger still, which is why capturing the full match matters so much.