How to Use the 401K Calculator

Project balance

1. Enter current age and retirement age. Their whole-year difference sets the projection horizon.
2. Enter current 401(k) balance and annual salary.
3. Enter the employee contribution rate as a percentage of salary.
4. Enter employer match rate and the first match band. Add a second tier only if your plan uses another band.
5. Enter expected annual return and annual salary growth.
6. Select Calculate projection and inspect the ending balance, contribution sources, match details, and year-by-year schedule.

Find contribution for a target

Switch modes, enter a target balance, and keep the other scenario assumptions. The solver checks the same projection at contribution rates between 0% and 100%. The displayed solved rate is rounded upward to 0.1 percentage point and the model is run again at that displayed rate.

Employer match fields

A 50% match through a 6% band means the model applies a 50% employer rate to the portion of the employee contribution rate up to 6% of salary. A second tier begins after the first band and covers only the additional band you enter.

Outputs and local exports

Copy result creates a plain-text summary. CSV and TSV provide structured tables. TXT, Markdown, JSON, HTML, and DOCX create local files. ZIP creates a local result kit containing the structured formats. Print / Save PDF uses the browser print dialog.

Planning boundary

This calculator does not enforce current IRS contribution limits or catch-up rules and does not model taxes, withdrawals, loans, RMDs, fees, inflation, vesting, plan eligibility, or retirement income. Verify important plan-specific decisions against current plan documents and appropriate professional guidance.