401(k) Calculator
Project how your 401(k) could grow by retirement. Enter your current balance, your total monthly contribution (yours plus any employer match), an expected annual return and the years until you retire to see your projected balance and the growth on top.
Grow your employer-sponsored retirement plan
A 401(k) is an employer-sponsored retirement plan that lets you invest a slice of each paycheck and let it grow over a career. Its three big advantages are automatic payroll contributions, tax-advantaged growth, and — for many workers — an employer match that adds free money on top of what you save. This calculator projects how your balance could grow from where it is today to the day you retire, so you can see the long-run payoff of contributing consistently and capturing every dollar of match.
The headline lesson of any 401(k) projection is that small, steady contributions over decades turn into a large balance, with compound growth eventually contributing far more than your own deposits. The earlier and more consistently you contribute, the more dramatic that effect becomes.
How to use this calculator
Enter your current 401(k) balance, your total monthly contribution — include your employer match if you receive one — an expected annual return, and the years to retirement. The calculator compounds monthly, projects the ending balance, and splits it into the money you contributed versus the growth on top. Try modeling the match included versus excluded to see exactly how much it adds over a full career.
Contribution amounts are capped by an annual IRS limit, and that limit changes most years, with a higher catch-up allowance once you reach a certain age. Rather than relying on a fixed number, check the current IRS limit for the year you are planning. The match your employer offers does not count against your personal contribution limit, which is part of why it is so valuable.
The employer match: free money
If your employer matches contributions — say, matching part of what you put in up to a percentage of salary — that is an immediate, guaranteed return on your savings before the market does anything. Contributing at least enough to capture the full match is one of the highest-return moves available to most savers; leaving match on the table is leaving compensation unclaimed. The match then compounds alongside your own money for decades.
Traditional vs. Roth 401(k)
Many plans offer two flavors. A traditional (pre-tax) 401(k) lowers your taxable income now; the balance grows tax-deferred and withdrawals in retirement are taxed as ordinary income. A Roth 401(k) is funded with after-tax dollars, so there is no break today, but qualified withdrawals — including all the growth — come out tax-free. The projected balance is the same for a given contribution; what differs is your after-tax outcome. Pre-tax tends to favor those who expect a lower tax rate in retirement, Roth those who expect a similar or higher one.
How it's calculated
The projection uses the future-value formula. A lump sum grows as FV = PV × (1 + r)n, where r is the periodic rate and n the number of periods; with monthly compounding the annual return is divided by 12 and years are multiplied by 12. Each monthly contribution — yours plus the match — is future-valued over its own remaining time and added in. Because returns are reinvested and earn their own returns, the balance grows faster the longer it runs, and the earliest contributions do the most work.
| Monthly contribution | You + employer add | Est. balance at retirement |
|---|---|---|
| $500 (you only) | $180,000 | ~$760,000 |
| $750 (with partial match) | $270,000 | ~$1,065,000 |
| $1,000 (with full match) | $360,000 | ~$1,370,000 |
Doubling the monthly contribution by capturing a match roughly doubles the projected balance — and a large share of the difference is growth, not just the extra deposits.
Tips and common mistakes
- Watch your vesting schedule. Employer match money may only become fully yours after you have worked a certain number of years. Leaving early can forfeit unvested match.
- Don't leave match on the table. Contributing below the match threshold means turning down guaranteed compensation.
- Roll over old accounts when you change jobs. A rollover into a new plan or an IRA keeps the money tax-advantaged and consolidated, instead of forgotten or cashed out.
- Avoid early withdrawals. Pulling money out before the qualifying retirement age generally triggers income tax plus an additional penalty, and permanently removes that money from compounding.
- Check the contribution limit yearly. Limits and catch-up allowances change, so verify the current IRS figure rather than relying on last year's number.
Frequently asked questions
Should I include my employer match?
Yes — add your contribution and the employer's together as the monthly figure. The match compounds just like your own money and significantly raises the projected balance.
What return should I assume?
Many savers model a diversified 401(k) at mid-to-high single digits over a long career, trending more conservative near retirement. Returns fluctuate and aren't guaranteed; this is a projection, not a promise.
Does this show pre-tax or after-tax dollars?
It projects the account balance in nominal dollars. Traditional 401(k) withdrawals are taxed as income later, while Roth 401(k) withdrawals can be tax-free — the balance shown is the same, but your after-tax outcome differs by account type.
What is a vesting schedule?
Vesting determines when employer-contributed match money fully belongs to you. Some plans vest immediately; others require you to stay for a set number of years before the match is entirely yours. Your own contributions are always 100% yours. If you might leave a job soon, check your plan's vesting rules.
How much can I contribute to a 401(k)?
The IRS sets an annual contribution limit that changes most years, with an additional catch-up amount allowed once you reach a certain age. Employer match does not count against your personal limit. Because the figures change, check the current year's IRS limit rather than relying on an old number.
What happens to my 401(k) when I change jobs?
You generally have a few options: leave it in the old plan, roll it into your new employer's plan, or roll it into an IRA. A direct rollover keeps the money tax-advantaged and avoids penalties. Cashing it out early usually triggers income tax plus an early-withdrawal penalty and ends its compounding.
Last updated: July 2026 · How we calculate
BriskToolbox provides estimates for general information only and is not financial advice. Investment returns are not guaranteed.