Formula and calculation method
Future value = P(1+i)^n + C × [(1+i)^n − 1] / i. Contributions and employer match are added at each month end.
A growth scenario, not a forecast. 401(k), IRA and Roth IRA labels refer to US account types; this tool does not enforce contribution limits, eligibility, vesting or withdrawal tax rules. Use zero employer match for accounts without it.
How to use retirement calculator
- Set Principal / amount. The example below uses 100000.
- Set Annual interest rate (%). The example below uses 6.
- Set Years. The example below uses 20.
- Set Monthly contribution. The example below uses 200.
- Set Employer match on contributions (%). The example below uses 0.
- Select Calculate to update the result. Reset restores the illustrated inputs. Copy, print or download your own result if you need a record.
Worked example
Example inputs
- Principal / amount
- 100000
- Annual interest rate (%)
- 6
- Years
- 20
- Monthly contribution
- 200
- Employer match on contributions (%)
- 0
- Projected balance
- 423,428.62661303
- Deposits and match
- 148000
- Investment growth
- 275,428.62661303
Factors affecting your result
A growth scenario, not a forecast. 401(k), IRA and Roth IRA labels refer to US account types; this tool does not enforce contribution limits, eligibility, vesting or withdrawal tax rules. Use zero employer match for accounts without it.
Changing principal / amount changes the scenario being evaluated. Adjust one input at a time when comparing results, keep a copy of the assumptions, and compare values using the same unit and period. A precise arithmetic result does not make an uncertain assumption precise.
Frequently asked questions
How does the retirement calculator work?
Future value = P(1+i)^n + C × [(1+i)^n − 1] / i. Contributions and employer match are added at each month end.
What inputs does Retirement Calculator need?
Enter principal / amount, annual interest rate (%), years, monthly contribution, employer match on contributions (%). Read the unit labels; percentages are entered as ordinary percentages, not decimal fractions.
How should I interpret the retirement calculator result?
A growth scenario, not a forecast. 401(k), IRA and Roth IRA labels refer to US account types; this tool does not enforce contribution limits, eligibility, vesting or withdrawal tax rules. Use zero employer match for accounts without it.
Are my retirement calculator inputs uploaded?
No. The calculation runs in this browser. Favorites, recent tool names, theme and formatting preferences may be saved locally, but calculation inputs are not sent to a calculation server or stored by this website. Shared links do not include entered values.
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