Money & Finance · Retirement projection
Estimate how a 401(k) balance could grow from your current balance, salary, employee contribution, employer match, expected annual return, salary growth, and retirement age. Or estimate the modeled contribution rate needed to reach a target balance.
Enter your assumptions and calculate a scenario.
| Year | Salary | Employee | Employer | Growth | End balance |
|---|
It models accumulation from a starting 401(k) balance, monthly employee contributions, a configurable employer match, a constant annual return assumption converted to an equivalent monthly rate, annual salary growth, and a retirement horizon.
The model grows the opening balance for each month, then adds that month's employee and employer contributions at the end of the month. Salary changes once per modeled year.
The target solver uses the same projection engine from 0% through 100%. It rounds the displayed solved rate upward to 0.1 percentage point and re-runs the projection at that displayed rate.
The first match rate applies through the first salary-share band you enter. If your plan uses another band, add a second tier. Actual eligibility, vesting, and matching rules come from your plan documents.
The ending balance is separated into your modeled contributions, employer matching, and estimated investment growth. Constant returns and salary growth are simplifying assumptions, not forecasts.
This version does not enforce current IRS limits or calculate taxes, withdrawals, loans, RMDs, Roth-vs-Traditional treatment, fees, inflation, vesting, plan eligibility, or retirement income. It is general mathematical planning, not individualized advice.
