About the Retirement (401k) Calculator
This free retirement (401k) calculator helps people in the United States get a quick, private estimate before they talk to a lender, insurer, employer or advisor. There is no signup, nothing is stored on our servers and every result updates instantly in your browser.
How this calculator works
The projection adds your contribution and employer match as a percentage of salary each month, compounds your balance at the expected return until retirement and shows a 4% rule yearly income estimate.
Worked example
A 30-year-old with $20,000, $70,000 salary, 8% contribution, 4% match and 7% return reaches roughly $1.5 million by 65. Change any input above to see how the result moves, which is the fastest way to understand which factor matters most for you.
Tips to get a better result
Always capture the full employer match. Increase your contribution by 1% each year. The 4% rule is a guideline, not a guarantee.
Key factors that change your result
Contribution rate, employer match, years invested and return all matter. Always contribute enough to receive the full employer match. The 4% rule is a rough guide, and Social Security, taxes and inflation are not modeled here.
Accuracy and limits
Every calculator on 100tools uses standard published formulas combined with average US market assumptions. Real offers depend on your credit profile, state, provider and personal circumstances, so treat the output as a starting point and confirm with an official quote or a licensed professional. Read more on our methodology page.
Frequently asked questions
What is the 4% rule?
A guideline that withdrawing 4% of your portfolio in year one lasts about 30 years.
Is this adjusted for inflation?
No. Figures are in future dollars.
Is the retirement (401k) calculator free to use?
Yes. Every calculator on 100tools is free with no registration.
Do you store the numbers I enter?
No. Calculations run in your browser and nothing you type is sent to our servers.