401(k) Calculator
Project your US 401(k) balance from employee contributions, employer match and market growth.
The 401(k) calculator projects how a workplace retirement account grows. You contribute a percentage of your salary, your employer matches part of it, and the whole balance compounds tax-deferred until you withdraw it in retirement.
How to use the calculator
- Enter your annual salary.
- Set the percentage you contribute — at least enough to capture the full employer match.
- Add your employer\u2019s match as a percentage of salary.
- Choose an expected return and the number of years to retirement.
How it is calculated
Balance grows by the annual return each year, compounding on the previous balance plus new contributions.
Worked example
$80,000 salary, 8% you, 4% employer, 7% for 30 years
Yearly contribution = $9,600, so $288,000 goes in over 30 years
Estimated balance ≈ $970,000, with about $682,000 coming from growth.
Who should use this calculator
- US employees deciding what percentage of salary to contribute to a workplace retirement plan.
- Anyone checking whether they are capturing the full employer match.
- People projecting a retirement balance decades ahead and wondering whether they are on track.
- Employees comparing a traditional pre-tax 401(k) with a Roth option.
Common mistakes to avoid
- Contributing less than the employer match. The match is an immediate return on your money. Not capturing it is the most expensive mistake in personal finance.
- Assuming the match is yours straight away. Many plans use a vesting schedule of three to six years. Leave earlier and you may forfeit part or all of the employer contribution.
- Ignoring fund fees. Expense ratios of 0.1% and 1% look trivial but compound over decades. A 1% difference on a large balance runs into thousands each year.
- Overlooking the annual limit. There is a cap on employee contributions, with a higher catch-up allowance for those aged 50 and over. Contributions above the limit can create a tax problem.
- Taking an early withdrawal. Withdrawing before age 59½ normally triggers income tax plus a 10% penalty. It undoes years of compounding for a short-term need.
The match comes first
A salary of $80,000 with an 8% employee contribution and a 4% employer match puts $9,600 a year into the plan, so $288,000 is contributed over thirty years. At a 7% annual return the projected balance is around $970,000, with roughly $682,000 of that coming from investment growth rather than your own money.
The order of priorities is consistent advice for a reason. Capture the full match first, because it is an immediate gain no investment can reliably beat. Then increase contributions as salary rises, until you are saving 10–15% of income including the match. Only after that does it make sense to compare the plan with other accounts, and any comparison should account for fees.
401(k) terms explained
- Employer match
- The amount your employer contributes based on your own contribution, usually a percentage of salary.
- Vesting
- The period you must work before the employer match becomes permanently yours.
- Contribution limit
- The maximum you can contribute from your own salary each year, with an extra allowance from age 50.
- Traditional versus Roth
- Traditional contributions are pre-tax and taxed on withdrawal; Roth contributions are after tax and withdrawn tax-free.
- Expense ratio
- The annual fee charged by a fund, deducted from returns before they reach you.
Traditional or Roth: how to decide
Traditional contributions come out of your salary before tax, so they reduce your taxable income today and are taxed when you withdraw in retirement. Roth contributions are made after tax and come out tax-free, including the growth. The question is whether your tax rate will be higher now or later.
Early in a career, when income is lower, Roth can be attractive because the tax you pay today is relatively cheap. In peak earning years, traditional contributions usually look better because the deduction is worth more now than the tax on withdrawals is likely to be later. Many plans let you split between the two, which hedges the decision without needing a precise forecast of future tax law.
Frequently asked questions
How much should I contribute to my 401(k)?
At minimum, contribute enough to earn your full employer match — it is an immediate return on your money. Many advisers suggest 10–15% of salary including the match for a comfortable retirement.
What is the 401(k) contribution limit?
For 2025 the employee limit is $23,500, rising to $31,000 if you are 50 or older. Contributions are made pre-tax in a traditional 401(k), or after tax in a Roth 401(k).
Does the employer match vest immediately?
Not always. Many plans use a vesting schedule of three to six years, so you keep the employer match only after working there for the required period. Check your plan documents.