401(k) Calculator — Free 2026

Understanding Your 401(k) Retirement Plan

A 401(k) plan is the most common employer-sponsored retirement savings vehicle in the United States. Named after Section 401(k) of the Internal Revenue Code, this plan allows employees to contribute a portion of their pre-tax income directly from their paycheck into a tax-advantaged investment account. The money grows tax-deferred, meaning you do not pay income tax on contributions or investment gains until you withdraw funds in retirement. For many Americans, a 401(k) forms the cornerstone of their retirement savings strategy alongside Social Security benefits.

This free 401(k) calculator helps you project how much your retirement account could be worth by the time you stop working. It accounts for your personal contributions, employer matching contributions, annual salary raises, expected investment returns, and the 2026 IRS contribution limits. The results update instantly as you adjust any input, making it easy to explore different scenarios and optimize your savings strategy.

How 401(k) Contributions and Employer Matching Work

When you participate in a 401(k) plan, you choose a contribution percentage that is automatically deducted from each paycheck before taxes. For example, if you earn $75,000 annually and contribute 6%, you would save $4,500 per year ($375 per month) into your 401(k). Because these are pre-tax contributions, your taxable income for the year drops to $70,500, providing an immediate tax benefit.

Most employers offer a matching contribution to incentivize participation. A common match formula is 50% of employee contributions up to 6% of salary. Using the same $75,000 salary example, your 6% contribution of $4,500 would receive a 50% employer match of $2,250. That is an instant 50% return on your contributed money before any investment gains. Financial advisors universally recommend contributing at least enough to capture the full employer match, as declining it is equivalent to turning down free money.

Some employers offer dollar-for-dollar matching (100%) or higher limits. The match percentage and limit vary by company, so check your plan documents or ask your HR department. This calculator lets you model any match formula by adjusting the employer match percentage and match limit fields.

2026 IRS Contribution Limits

The IRS sets annual limits on how much employees can contribute to their 401(k) accounts. For 2026, the standard employee contribution limit is $24,500. If you are age 50 or older at any point during the year, you can make additional catch-up contributions of $8,000, bringing your total employee contribution limit to $32,500. Workers aged 60 to 63 qualify for an enhanced super catch-up contribution of $11,250, for a total limit of $35,750. These limits apply to employee deferrals only and do not include employer matching contributions.

This calculator automatically enforces these limits. If your contribution percentage would exceed the annual IRS limit based on your salary, the calculator caps your contribution at the applicable limit. For those approaching or over age 50, the catch-up contribution is automatically factored in, giving you a more accurate projection of your retirement savings.

The Power of Compound Growth in Your 401(k)

The true wealth-building power of a 401(k) comes from decades of compound growth. When your investments generate returns, those returns are reinvested and begin generating their own returns. Over a 35-year career, this compounding effect can turn relatively modest monthly contributions into a substantial retirement nest egg. For example, contributing $375 per month with a $187.50 employer match ($562.50 total monthly) at a 7% average annual return for 35 years produces a balance of approximately $925,000 — even though total contributions only amount to about $236,250. The remaining $688,750 is pure investment growth.

The expected annual return you enter should reflect your anticipated average return over the entire accumulation period. Historically, a diversified portfolio of stocks and bonds has returned between 6% and 10% annually over long periods, though past performance does not guarantee future results. A 7% assumption is commonly used for moderate-risk portfolios and accounts for inflation-adjusted real returns. Conservative investors may prefer 5-6%, while aggressive investors might model 8-9%. Use our compound interest calculator to explore how different return rates affect long-term growth.

Annual Salary Raises and Their Impact

If your salary increases over time, your 401(k) contributions grow proportionally, assuming you maintain the same contribution percentage. Even a modest 2% annual raise significantly boosts lifetime contributions. On a $75,000 salary growing at 2% per year for 35 years, your final salary would be approximately $150,000, and your cumulative contributions would be substantially higher than if your salary had remained flat. This calculator models salary growth year by year, applying your raise percentage annually and recalculating contributions and employer matches accordingly.

The 4% Safe Withdrawal Rule

The 4% rule is a widely cited guideline for retirement spending. It suggests that withdrawing 4% of your portfolio in the first year of retirement, then adjusting for inflation each subsequent year, gives you a high probability of not outliving your savings over a 30-year retirement. This calculator displays your estimated monthly income based on this rule. For instance, a $1,000,000 retirement balance would generate approximately $40,000 per year or $3,333 per month.

Keep in mind that the 4% rule is a starting point, not a guarantee. Your actual safe withdrawal rate depends on market conditions, your asset allocation, other income sources like Social Security, and your individual spending needs. Consider using our retirement calculator for a more comprehensive retirement income projection.

Strategies to Maximize Your 401(k)

First, always contribute enough to get the full employer match. Second, increase your contribution percentage by 1% each year, especially when you receive a raise. Third, if you are over 50, take advantage of catch-up contributions. Fourth, review your investment allocation periodically to ensure it aligns with your risk tolerance and time horizon. Finally, avoid early withdrawals, which incur a 10% penalty plus income taxes and permanently reduce your compounding base.