Understanding your withdrawal projection
The table below shows the general relationship between the initial withdrawal rate and how long a balance tends to last under this inflation-adjusted model, holding the assumed return and inflation rate constant.
| Initial withdrawal rate | General effect on how long the balance lasts |
|---|---|
| Lower initial withdrawal rate (e.g., 3-4%) | Balance tends to last longer, or indefinitely, especially when the assumed return exceeds the withdrawal-plus-inflation drag |
| Moderate initial withdrawal rate (e.g., around 5%, the calculator's default) | Balance typically lasts multiple decades but is not indefinite under this model's growing, inflation-adjusted withdrawal |
| Higher initial withdrawal rate (e.g., 7%+) | Balance tends to be exhausted considerably sooner, since withdrawals outpace investment growth by a wider margin each year |
- This calculator uses a single fixed assumed investment return applied every year; actual investment returns vary significantly year to year, and a sequence of poor early returns can exhaust a balance faster than this smooth, constant-return projection suggests — a risk retirement researchers refer to as sequence-of-returns risk.
- The 'Trinity study' and its many follow-up analyses are widely cited academic and practitioner research on safe withdrawal rates using historical U.S. market data across many different starting years; results vary by the specific time period, asset allocation and withdrawal rate examined, and this calculator does not replicate that full historical simulation — it computes a single scenario from the inputs entered.
- This calculator does not model Social Security income, required minimum distributions, taxes on withdrawals, or other income sources that would typically supplement or interact with a retirement portfolio's withdrawal in practice.
What is a retirement withdrawal calculation?
A retirement withdrawal calculation projects, year by year, how a starting balance changes when it earns an assumed investment return but also funds an annual withdrawal that grows each year to keep pace with inflation — the combination retirement researchers typically model to estimate how long savings will actually last in real, inflation-adjusted terms.
The 'safe withdrawal rate' concept, most associated with the Trinity study and related retirement research, examines what initial withdrawal rate (the first-year withdrawal as a percentage of the starting balance) a portfolio can sustain over a long retirement without running out, given historical patterns of investment returns and inflation. This calculator computes the outcome for a specific, single set of assumed return and inflation figures rather than testing across historical scenarios.
Because the withdrawal amount increases with inflation every year in this model, the balance faces two simultaneous pressures: a fixed real (inflation-adjusted) standard of living funded by a growing nominal withdrawal, against a balance that only grows at the assumed investment return — this is a materially different, generally more conservative calculation than a level, never-increasing nominal withdrawal.
How to use this retirement withdrawal calculator
- Enter the starting retirement balance.
- Enter the annual withdrawal amount you plan to take in the first year.
- Enter the expected annual investment return on the remaining balance.
- Enter the assumed annual inflation rate the withdrawal will be adjusted for each year.
- Read how many years the balance is projected to last, the initial withdrawal rate, and the first-year withdrawal amount.
The formula behind the withdrawal projection
Each simulated year, the balance first grows by the assumed investment return, then the year's withdrawal — the first-year amount increased by the inflation rate compounded for that many years — is subtracted. This repeats year by year until the balance reaches zero or 100 years have been simulated, whichever comes first.
On the calculator's default example — an $800,000 starting balance, a $40,000 first-year withdrawal (a 5.00% initial withdrawal rate), a 5% annual investment return, and 3% annual inflation — the balance lasts approximately 27 years before being exhausted under this year-by-year simulation.
Common mistakes
- Assuming a single average return figure captures real-world risk — a portfolio experiencing poor returns in the early years of retirement can be exhausted meaningfully faster than this constant-return projection, even if the long-run average return matches the assumption.
- Forgetting that this calculator increases the withdrawal amount every year for inflation, which is a different and generally more conservative assumption than a level, unchanging nominal withdrawal amount.
- Treating the projected years as a guarantee rather than a projection based on fixed assumptions — actual outcomes depend on the sequence and size of real investment returns and real inflation, neither of which can be known in advance.
- Ignoring other income sources, such as Social Security or a pension, that would typically reduce how much needs to be drawn from an investment portfolio, which this calculator does not incorporate.
- Not accounting for taxes on withdrawals, which reduce the amount actually available to spend relative to the gross withdrawal figures this calculator projects.
Pertanyaan yang sering diajukan
How long will $800,000 last with a $40,000 annual withdrawal?
Using a first-year withdrawal of $40,000 (a 5.00% initial withdrawal rate) that increases 3% annually for inflation, a 5% annual investment return, and an $800,000 starting balance, the balance is projected to last approximately 27 years before being exhausted under this year-by-year simulation.
What is a safe withdrawal rate in retirement?
A safe withdrawal rate is the initial percentage of a retirement portfolio that can be withdrawn in the first year, with subsequent withdrawals adjusted for inflation, while maintaining a low probability of exhausting the portfolio over a specified retirement length. The concept is most associated with the Trinity study and its many follow-up analyses using historical U.S. market data; this calculator computes the outcome for one specific set of assumed return and inflation figures.
Does this calculator account for changing investment returns each year?
No. This calculator applies a single fixed assumed annual return every year of the projection. Real investment returns vary considerably year to year, and a sequence of below-average returns early in retirement — known as sequence-of-returns risk — can exhaust a balance faster than a smooth, constant-return projection would suggest.
Why does the withdrawal amount increase every year in this calculator?
The calculator increases the withdrawal amount by the assumed inflation rate each year, so the real (inflation-adjusted) purchasing power of the withdrawal stays roughly constant over time. This is a more conservative and realistic assumption for long retirements than a withdrawal amount that never increases in nominal dollars.
Does this calculator include Social Security or pension income?
No. This calculator projects only the balance entered against the withdrawal, return and inflation assumptions provided. Social Security, pension income, part-time work, or other income sources are not modeled and would typically reduce how much needs to be drawn from an investment portfolio in a real retirement plan.
Referensi
- Cooley PL, Hubbard CM, Walz DT. Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable. AAII Journal, 1998 (the 'Trinity study').
- U.S. Securities and Exchange Commission (SEC), Investor.gov. Retirement planning and withdrawal strategy resources. investor.gov.
- Social Security Administration (SSA). Retirement benefits and planning resources. ssa.gov.
- Financial Industry Regulatory Authority (FINRA). Retirement income and withdrawal planning basics. finra.org.