Retirement Calculator
Retirement projection assumptions
Estimate savings at retirement and how long that balance could fund level annual withdrawals. The model assumes one constant return before and during retirement and contributions at the end of each year.
Formula and method
Savings at retirement uses future value. Withdrawal duration solves the present value of a level annuity; when expected annual growth covers spending, the simplified model reports an indefinite duration.
Worked example
Use conservative return assumptions and test several spending levels rather than relying on one projection.
How to interpret the result
Treat the output as a stress-testing starting point. Compare conservative and optimistic returns, then test higher spending and a later or earlier retirement date. The spending-duration estimate is especially sensitive to inflation and poor returns early in retirement, neither of which is represented by a constant-return model.
Important limitations
- Inflation, taxes, Social Security, sequence-of-returns risk, fees and required distributions are excluded.
- This educational estimate is not financial advice.
Common questions
Does annual spending increase with inflation?
No. The entered spending is held level in the simplified withdrawal calculation. A real plan should model rising costs and distinguish today's dollars from future nominal dollars.
Are Social Security and pensions included?
No. The model only compares the projected account balance with the entered annual spending. Guaranteed income, taxes, required distributions, fees, and healthcare costs must be considered separately.
Source and further reading
Investor.gov retirement resources
Related tools
Method and examples reviewed September 8, 2026.