How the 401k Calculator Works
This calculator projects your 401k balance by compounding your annual contributions, your employer's matching contributions, and investment returns over your chosen time horizon. It starts with your current balance and adds both your contribution (a percentage of salary) and the employer match each year before applying the annual return.
For example, if you earn $75,000 and contribute 10%, you put in $7,500 per year. If your employer matches 50% of contributions up to 6% of salary, they add $2,250 per year. At 7% annual growth over 30 years starting from $25,000, your 401k could grow to over $1.1 million.
Maximize Your 401k
Always contribute enough to capture the full employer match. Increase your contribution by 1% each year — you will barely notice the difference in your paycheck. Choose low-cost index funds to keep fees under 0.2%. And never cash out a 401k when changing jobs — roll it into an IRA instead.
Related Calculators
Frequently Asked Questions
How much should I contribute to my 401k?
Financial advisors commonly recommend contributing at least enough to get the full employer match — that is free money. Beyond that, 15% of gross income is a good target.
What is the 401k contribution limit?
For 2026, the employee contribution limit is $23,500 (under 50) or $31,000 (50+). Employer contributions are additional.
What return should I assume?
A diversified portfolio of stocks and bonds has historically returned 7-10% annually before inflation. 7% is a common conservative assumption.
Should I choose Roth 401k or traditional?
Traditional 401k contributions reduce your taxable income now; Roth 401k contributions grow tax-free. If you expect higher taxes in retirement, Roth is often better.