401k Calculator
Use this 401k calculator to estimate how your retirement account could grow between now and your target retirement age. Enter your age, salary, contribution rate, employer match, current balance, and investment assumptions. The tool returns a projected balance, total employee and employer contributions, investment growth, and an estimated annual retirement income. No manual compounding required.
A 401k calculator helps you turn today’s paycheck decisions into a future retirement snapshot. It is built for employees who want to know whether their current deferral rate, employer match, and investment assumptions are likely to produce enough savings by retirement. The calculator uses the numbers you enter, including salary growth and age-based IRS deferral limits, to build a year-by-year projection. You can see your own contributions, employer match dollars, compounding growth, and a safe-withdrawal income estimate. Because the math runs in your browser, you can test different contribution rates and retirement ages without sharing personal data. Use it as a planning aid, not a guarantee, and revisit the numbers whenever your salary or goals change.
How to Use the 401k Calculator
Choose a currency symbol from the dropdown.
Enter your current age and target retirement age.
Add your current annual salary and expected annual salary growth.
Input your current 401k balance and contribution rate as a percentage of salary.
Set the employer match rate and match cap.
Provide an expected annual return and safe withdrawal rate.
Press Calculate or load a quick example such as Early Starter, Typical Saver, Aggressive Saver, Catch-Up, or Super Catch-Up.
Review the projected balance, contribution totals, employer match, investment growth, annual income estimate, milestones, and year-by-year table.
How the 401k Calculator Formula Works
Formula: FV = PV(1 + r/12)^(12t) + PMT × [((1 + r/12)^(12t) − 1) ÷ (r/12)]
This is the core monthly compounding structure, but the calculator does not use one fixed PMT for the entire projection. It rebuilds contributions year by year because salary grows and IRS deferral limits change with age.
Formula: Employee Contribution = min(Salary × Contribution Rate, IRS Employee Limit for That Age)
Formula: Employer Match = Match Rate × min(Employee Contribution, Match Cap % × Salary)
Formula: Investment Growth = Projected Balance − Starting Balance − Total Employee Contributions − Total Employer Match
Formula: Projected Annual Retirement Income = Projected Balance × (Safe Withdrawal Rate ÷ 100)
The IRS employee limits used in the code are $24,500 base, $8,000 catch-up for age 50 and older, and $11,250 super catch-up for ages 60 through 63. The age used for the limit is the age reached at the end of each projection year. Negative numeric entries are treated as zero. If retirement age is less than or equal to current age, the calculator shows an invalid age range message and stops. The currency selector changes the displayed symbol only; it does not convert money. The tool does not enforce the total 415(c) limit, the compensation limit, or the SECURE 2.0 Roth catch-up rule. If the expected return is zero, the balance grows only from contributions.
Worked Example
Assume a 45-year-old wants to retire at 55. The current salary is $100,000 with 2% annual salary growth, the current 401k balance is $150,000, the contribution rate is 15%, the employer matches 50% up to 6% of salary, the expected annual return is 6%, and the safe withdrawal rate is 4%.
Years to retirement = 55 − 45 = 10. Monthly return = 6% ÷ 12 = 0.5%.
In year one, the employee contribution is min(15% × $100,000, $24,500) = $15,000. The employer match is 50% × min($15,000, 6% × $100,000) = 50% × $6,000 = $3,000. Total first-year contribution = $18,000. Salary rises 2% each year, so contributions rise at roughly the same pace. The employee contribution stays below the IRS limit throughout this example.
After 10 years of monthly compounding, the projected balance is about $532,000. Total employee contributions are about $164,200, employer match is about $32,800, and investment growth is about $185,100. At a 4% withdrawal rate, projected annual retirement income is about $21,300. The calculator would label this “Solid Retirement Savings” because the balance is at least $500,000 but below $1,000,000. The takeaway: the projection is respectable, but increasing the contribution rate or delaying retirement would move it closer to the millionaire milestone.
Frequently Asked Questions
How does this 401k calculator project my retirement balance?
It starts with your current balance, then applies monthly compounding using your expected annual return. Each year it adds employee contributions, employer match, and salary growth, while respecting the IRS employee deferral limit for that age. The final result is the projected balance at your chosen retirement age.
Does the 401k calculator include employer match?
Yes. The employer match is calculated as match rate multiplied by the smaller of your employee contribution or the match cap percentage of salary. If your contribution rate is below the match cap, the calculator may warn that you are not capturing the full match.
What IRS contribution limits does this 401k calculator use?
The code uses 2026 limits: $24,500 base employee deferral, $8,000 catch-up for age 50 and older, and $11,250 super catch-up for ages 60 through 63. It does not enforce the total 415(c) limit or the compensation limit.
How is the employer match calculated in this tool?
The match is match rate × min(employee contribution, match cap % × salary). For example, a 50% match up to 6% of salary means the employer pays 50 cents for each dollar you contribute, but only on the first 6% of pay.
What happens if my contribution rate is below the match cap?
You may receive a smaller employer match than you could. The calculator adds a recommendation when your contribution rate is below the match cap, because increasing your deferral to the cap can capture additional employer dollars.
Can I model catch-up contributions after age 50?
Yes. The calculator automatically increases the employee deferral limit when the projection year reaches age 50. A larger super catch-up limit is applied for ages 60 through 63. The actual contribution still depends on your salary and chosen contribution rate.
What is the difference between contribution rate and match cap?
Contribution rate is the percentage of your salary you defer into the 401k. Match cap is the maximum percentage of salary your employer will consider when calculating the match. A 10% contribution rate with a 6% match cap means only the first 6% of salary is match-eligible.
How does salary growth affect my 401k projection?
Salary growth raises your future contributions because the deferral is a percentage of pay. A higher salary growth rate increases both employee contributions and employer match dollars over time. Setting salary growth to zero keeps contributions flat in nominal terms.
What does safe withdrawal rate mean in this 401k calculator?
Safe withdrawal rate is the percentage of the projected balance you plan to withdraw each year in retirement. The calculator multiplies the final balance by this rate to estimate annual retirement income. It does not model taxes, fees, or market volatility during retirement.
Does the calculator account for taxes?
No. The projection does not subtract income taxes, capital gains taxes, or required minimum distributions. Traditional 401k withdrawals are generally taxable, while Roth 401k withdrawals may be tax-free if qualified. Consult a tax professional for your situation.
Why does the calculator show an invalid age range?
It shows that message when retirement age is less than or equal to current age. The tool needs at least one year between current age and retirement age to project growth and contributions.
