Savings Withdrawal Calculator
Enter your savings balance, an annual interest rate, and either a withdrawal amount or a target number of withdrawals to instantly see how long your money will last, how much you can take each period, or what balance will remain. The calculator also shows a year-by-year depletion chart and a full withdrawal schedule. Set any one of the four main figures to zero and the calculator solves for it.
What is a savings withdrawal calculator?
A savings withdrawal calculator models how a lump sum of savings shrinks over time as you take regular payments from it. It uses the time-value-of-money annuity formula to answer three related questions: how long will the money last at a given withdrawal rate, how much can you withdraw each period to make the savings last a specific number of years, or what balance will be left after a fixed number of withdrawals. Because the savings continue to earn interest or investment returns between withdrawals, the result is almost always better than simple division: a 250,000 balance earning 5% annually can sustain 1,200-per-month withdrawals for over 30 years rather than the 17.4 years you would expect with no growth.
The formula: present value of an annuity
The core formula is the present value of an ordinary annuity: PV = PMT x [1 - (1+r)^(-n)] / r, where PV is the starting balance, PMT is the periodic withdrawal amount, r is the periodic interest rate (annual rate divided by payment frequency), and n is the total number of periods. To find how long money lasts, the formula is rearranged to solve for n: n = -ln(1 - r x PV / PMT) / ln(1+r). To find the withdrawal amount, it becomes PMT = PV x r / [1 - (1+r)^(-n)]. This calculator also supports an optional annual growth rate on withdrawals so you can model inflation-adjusted spending where you increase your withdrawal by, say, 2-3% each year to preserve purchasing power.
The 4% rule and sustainable withdrawal rates
The 4% rule, derived from the Trinity Study of 1998, found that a retiree withdrawing 4% of a diversified portfolio in the first year, and adjusting for inflation thereafter, had a high probability of not running out of money over 30 years. This rule of thumb is a useful starting point, but it assumes a mix of equities and bonds, a specific 30-year horizon, and historical U.S. market returns. Longer retirement horizons, lower expected returns, or conservative all-cash portfolios may require a lower withdrawal rate of 3% or even 2.5%. Higher-risk tolerances or shorter timelines may allow 5-6%. The reference table above summarizes the general relationship between withdrawal rate and estimated longevity.
How to use the solve modes
The calculator offers three solve modes. In "How long will money last" mode, enter your starting balance, annual rate, withdrawal frequency, and the fixed withdrawal amount, and the calculator tells you the duration in years before the balance reaches zero. In "How much can I withdraw" mode, enter the starting balance, rate, and the number of withdrawals you want to make (for example 360 for 30 years of monthly payments), and the calculator returns the maximum sustainable payment per period. In "What balance remains" mode, enter the starting balance, rate, withdrawal amount, and number of withdrawals, and you see exactly how much will be left at the end of the period, which is useful for estate planning or if you want to preserve a specific legacy balance.
Sustainable withdrawal rate guidelines
| Annual withdrawal rate | Estimated longevity | Sustainability |
|---|---|---|
| 2-3% | 40+ years (often indefinitely) | Very high |
| 4% | 30 years (the classic rule) | High |
| 4.5-5% | 20-25 years | Moderate |
| 5-6% | 15-20 years | Low |
| Above 6% | Under 15 years | Very low |
Commonly referenced annual withdrawal rates and their estimated portfolio longevity, assuming a diversified investment portfolio.
Frequently asked questions
How long will 250,000 last with 1,000 per month withdrawals?
At 0% interest it lasts 250 months, about 20.8 years. At 5% annual interest compounding monthly, the same 250,000 lasts roughly 32 years, because the interest earned each month partially offsets the withdrawal. Enter your specific balance and rate into this calculator to get the exact figure for your situation.
What is the 4% rule?
The 4% rule is a retirement planning guideline suggesting you can withdraw 4% of your starting portfolio value in year one and then adjust each year for inflation, with a high probability of the portfolio lasting 30 years. It originated from William Bengen's 1994 research and was later popularized by the Trinity Study. It assumes a balanced portfolio of stocks and bonds rather than a simple savings account, so the actual sustainable rate for cash savings earning today's rates may differ.
What happens if my interest rate is lower than my withdrawal rate?
If you withdraw more than your balance earns in interest each period, the balance shrinks a little with every withdrawal. The calculator correctly models this declining balance and tells you when it will reach zero. If your withdrawal equals exactly what the balance earns, the principal is preserved indefinitely. If your withdrawal is less than the interest earned, the balance actually grows over time.
Should I adjust my withdrawals for inflation?
For retirement planning spanning 15 years or more, ignoring inflation means your purchasing power falls year by year. Setting a 2-3% annual withdrawal growth rate in the calculator models the real-world effect of raising your withdrawal each year to keep pace with rising prices. The trade-off is that inflation-adjusted withdrawals start lower but rise over time, and they deplete the balance faster than a fixed withdrawal plan.
Is the withdrawal schedule accurate for a savings account vs. an investment portfolio?
The schedule is precise for a savings account with a fixed, guaranteed interest rate. For an investment portfolio, the actual rate of return varies each year, so the schedule is a projection based on your assumed average rate. Sequence-of-returns risk - getting poor returns early in retirement - can deplete a portfolio much faster than the average rate implies. A financial planner can model Monte Carlo scenarios that account for this variability.