Savings Withdrawal Calculator United States
This savings withdrawal calculator finds how long your savings last at a fixed monthly withdrawal, or a sustainable withdrawal for a target number of years.

What it does
The Savings Withdrawal Calculator shows how long a balance lasts at a fixed monthly withdrawal, or the sustainable withdrawal that exhausts a balance over a chosen number of years, given a monthly-compounded return.
Data sources & parameters
This calculator uses standard financial formulas and runs entirely in your browser. It needs no external rate data — your result is computed only from the values you enter above.
We always strive to use the latest data for every variable so our results and reports are as accurate as possible. Even so, errors are possible — you should not rely on this tool or its report alone, and we accept no liability for any decision made based on it.
The formula
Months = -ln(1 - (B*i)/W) / ln(1+i); Safe W = B*i / (1 - (1+i)^-n)
How it works
In duration mode it solves a depleting annuity for the number of months. In safe-withdrawal mode it solves the annuity payment that empties the balance over your target horizon.
Where it is used
- Seeing how long a nest egg lasts at a set spend
- Finding a sustainable monthly draw for a fixed period
- Stress-testing a drawdown against different return rates
Worked example
Drawing $1,000.00 a month from $100,000.00 earning 5% a year, the balance lasts about … years (… months), with … of interest earned along the way.
What the savings withdrawal calculator does
The calculator helps you plan how to spend down savings without running out too soon. Start with a monthly withdrawal to find how long the money lasts, or start with a number of years to find the monthly withdrawal that fits. Both use the same arithmetic, so you can switch between them. You enter a starting balance, either a monthly withdrawal or a target number of years, and an expected annual return, compounded monthly.
When you withdraw, each payment shrinks the balance that earns future growth, so the size of withdrawals matters. The tool tracks how the balance behaves as you take money out while the remainder keeps earning a return.
How long will my money last
In duration mode the calculator solves for the number of months the balance can support your withdrawal before reaching zero. Each month the remaining balance earns a share of the annual return, and the withdrawal is subtracted.
Because the balance keeps earning, the answer is usually longer than the balance divided by the withdrawal. The higher the assumed return, the more of each withdrawal is offset by growth. The result is shown in months and years, so you can match it to a retirement horizon, a gap between incomes or another timeline.
Finding a sustainable withdrawal
In safe-withdrawal mode you enter how many years the money should last, and the calculator finds the monthly amount that draws the balance to exactly zero over that period: the annuity payment the sum can support at your chosen return.
This suits a defined horizon, such as funding a gap of a set number of years or a drawdown to a certain age. Because it exhausts the balance at the end, you may want to withdraw somewhat less to leave a cushion or an inheritance.
The return assumption
A small change in the assumed return can noticeably shift how long the balance lasts or how much you can withdraw, because the effect compounds over many months. Run the calculation at a low, medium and high rate instead of trusting one optimistic figure. A conservative assumption leaves room for years when markets underperform.
If your monthly withdrawal is smaller than the return the balance earns each month, the balance grows even as you draw from it and never runs out. The calculator flags this as effectively perpetual. It is the point where you are living on the growth alone without spending principal.
Inflation and taxes
The calculator uses a constant return and a fixed withdrawal, so it leaves out inflation and tax. Prices tend to rise, so a fixed withdrawal buys a little less each year. Entering a real return, your expected return minus expected inflation, makes the withdrawal figure roughly represent constant purchasing power.
Withdrawals from different account types are taxed differently, and the calculator deducts no tax. If your withdrawals are taxable, you may need to take out more than your spending target to cover the tax, which shortens how long the balance lasts. Treat the output as a pre-tax figure.
Reading your result
The output shows how long the savings last in years and months, the monthly withdrawal, the total withdrawn over the period, and the interest earned along the way, which shows how much of your spending is funded by growth versus principal.
This is a smooth, average-case projection. Real returns arrive unevenly, and poor years early in a drawdown can shorten how long money lasts more than the average suggests. Revisit the figures when your balance, spending or return outlook changes, and consider professional advice for decisions that depend on them.
This is general information only and not financial advice.
About This Savings Withdrawal Calculator
Use this savings withdrawal calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.
