Understanding your 401(k) calculator results
Estimate retirement contributions including a configurable employer matching assumption. The main result is a starting point for your decision. Review the other figures in the results panel to understand how much of the outcome comes from your inputs and which assumptions have the largest effect.
A change in rate, time horizon or recurring amount can produce a different answer. Try a second scenario before using an estimate in a household or business decision.
How the calculation works
Employee contributions and hypothetical employer match are added monthly, then projected to retirement.
Monthly employer match = salary ÷ 12 × eligible salary share × match rate; grow contributions with the portfolio.
Inputs are validated in your browser, and results use standard mathematical models with the assumptions displayed alongside the output. Depending on the calculator, the chart may show a declining balance, growing savings or a comparison between costs. Read the calculation methodology.
A practical example
A 6% salary contribution with employer matching can build a different savings path than employee saving alone.
Use the starting values above to reproduce a scenario, then replace them with your figures. The example is illustrative, not a forecast of rates or market performance.
Important assumptions and limitations
This tool uses numbers you supply and does not fetch personal account information or live lender offers. Interest, inflation, taxes, market returns, lender fees and legal rules vary by product and location. Where a figure is not an actual quote or official rate, treat it as a hypothetical input and verify it independently.
Official resources and further reading
For independent financial context, review a primary source related to this category. Source information may change after this page is published.
Frequently asked questions
How does the 401(k) calculator work?
Employee contributions and hypothetical employer match are added monthly, then projected to retirement.
What should I change to compare 401(k) calculator scenarios?
Start with current age, target retirement age, starting balance. A 6% salary contribution with employer matching can build a different savings path than employee saving alone. Every output is based on your own inputs.