401(k) Retirement Calculator: Plan Your Future With Confidence
A 401(k) plan is one of the most powerful retirement savings vehicles available to American workers. Offered through employers, a 401(k) allows you to contribute a portion of your pre-tax salary to a tax-advantaged investment account that grows over time. Many employers sweeten the deal by matching a percentage of your contributions — effectively giving you free money for saving. This calculator helps you project your 401(k) balance at retirement based on your current savings rate, employer match, expected returns, and salary growth, so you can make informed decisions about your retirement strategy.
How a 401(k) Works
When you enroll in a 401(k) plan, you choose a percentage of each paycheck to contribute. These contributions are deducted before federal income tax is calculated, which reduces your taxable income for the year. The money is then invested in a selection of mutual funds, index funds, or target-date funds chosen from your plan's options. Your investments grow tax-deferred, meaning you don't pay capital gains or income taxes on the returns until you withdraw funds in retirement. Traditional 401(k) withdrawals are taxed as ordinary income; Roth 401(k) contributions are made with after-tax dollars but qualified withdrawals are tax-free.
Employer Matching: Don't Leave Free Money on the Table
Many employers match a portion of your 401(k) contributions, and this is widely considered the best guaranteed return on investment you can get. A common match formula is 50% of employee contributions up to 6% of salary. If you earn $75,000 and contribute 6% ($4,500), your employer adds $2,250 — an instant 50% return on that money. Some employers match dollar-for-dollar, and a few offer even more generous formulas. The single most important 401(k) strategy is to contribute at least enough to capture your full employer match. Anything less means you are turning down part of your compensation package.
2025 Contribution Limits
The IRS sets annual limits on how much employees can contribute to their 401(k) plans. For the 2025 tax year, the employee elective deferral limit is $23,500. If you are age 50 or older at any point during the calendar year, you can make an additional $7,500 catch-up contribution, bringing your personal maximum to $31,000. These limits apply only to your own contributions — employer matching dollars are separate and do not count toward the employee limit. The combined employer-plus-employee limit for 2025 is $70,000 ($77,500 including catch-up). These limits are adjusted periodically by the IRS to keep pace with inflation.
The 4% Rule and Monthly Retirement Income
Once you retire, you need a strategy for turning your 401(k) balance into a sustainable income stream. The 4% rule, based on the widely cited Trinity Study, suggests that withdrawing 4% of your portfolio in the first year of retirement and adjusting that amount for inflation each subsequent year gives you a high probability of your savings lasting at least 30 years. For example, a $1,000,000 portfolio would support $40,000 per year, or roughly $3,333 per month. This calculator uses the 4% rule to estimate your potential monthly retirement income so you can gauge whether your savings trajectory is on track.
Investment Returns and Salary Growth
Historical stock market returns have averaged roughly 10% annually before inflation (about 7% after inflation). A balanced portfolio of stocks and bonds might average 6–8% depending on allocation and market conditions. This calculator lets you input your own expected return rate to match your risk tolerance and investment strategy. It also factors in annual salary increases, which affect your dollar contributions and employer match over time. Even modest 2–3% annual raises compound significantly over a 30-year career.
Frequently Asked Questions
How much should I contribute to my 401(k)?
At minimum, contribute enough to get your full employer match. Financial planners typically recommend saving 10–15% of gross income for retirement. If you can't start there, increase your contribution by 1% each year until you reach your target. Many plans offer automatic escalation features that do this for you.
When can I withdraw from my 401(k) without penalty?
You can take penalty-free withdrawals starting at age 59½. Withdrawals before that age generally incur a 10% early withdrawal penalty in addition to income tax, though exceptions exist for hardship, disability, and certain other qualifying events. Required minimum distributions (RMDs) begin at age 73 under current rules.
What happens to my 401(k) if I change jobs?
You have several options: leave the funds in your former employer's plan (if allowed), roll the balance into your new employer's 401(k), roll it into a traditional IRA, or cash it out (not recommended due to taxes and penalties). A direct rollover to an IRA or new 401(k) preserves the tax-deferred status with no penalties.
This 401(k) retirement calculator is completely free, runs entirely in your browser, and stores nothing on a server. Bookmark this page to revisit whenever you want to check your retirement projections.