Retirement Withdrawal Calculator — Rex's Toolbox

Rex says

The 4% rule is a starting point, not a law. What actually decides the outcome is the gap between your return and inflation — and whether you can flex spending in bad years.

Try a scenario

Click to load — tweak from there.

Inputs

Retirement savings($)

Annual withdrawal in year one($)

Other annual income($)

Social Security, pension, rental.

Annual spending target($)

Assumed annual return(%)

Assumed inflation(%)

Years you need it to last

Result

Years the portfolio lasts

Survives your horizon?

Yes — money outlasts the horizon

Ending balance

$133,706

Max sustainable first-year withdrawal

$43,183

That as a withdrawal rate

5.08%

The 4% rule figure

$34,000

Your current withdrawal rate

4.94%

Spending gap not covered

A 4.94% draw is inside the 5.08% your assumptions support — you have room, and the ending balance is your cushion against a bad first decade.

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How to use this

1Enter retirement savings ($).
2Enter annual withdrawal in year one ($).
3Enter other annual income ($) — Social Security, pension, rental..
4Enter annual spending target ($).
5Enter assumed annual return (%).
6Enter assumed inflation (%).
7Enter years you need it to last.
8Read your years the portfolio lasts on the right — it updates as you type.
9Hit Share to keep the scenario or send it to someone.

About this calculator

The question behind every retirement plan is whether the money outlasts you. This calculator runs a year-by-year simulation: your portfolio grows at your assumed return, your withdrawal rises with inflation, and the balance either survives the horizon or runs out — and it tells you the year. It also reports the 4% rule figure and the maximum inflation-adjusted withdrawal your horizon can actually support.

FormulaEach year: ending balance = (starting balance − withdrawal) × (1 + return); the withdrawal then grows by inflation. The sustainable figure is the largest year-one withdrawal that still leaves a positive balance at the end of your horizon.

Worked example

Using the values the calculator loads with:

Inputs

Retirement savings: 850000 $
Annual withdrawal in year one: 42000 $
Other annual income: 30000 $
Annual spending target: 72000 $
Assumed annual return: 6 %
Assumed inflation: 2.7 %
Years you need it to last: 30

Results

Years the portfolio lasts: 30
Survives your horizon?: Yes — money outlasts the horizon
Ending balance: $133,705.59
Max sustainable first-year withdrawal: $43,182.67
That as a withdrawal rate: 5.08%
The 4% rule figure: $34,000.00
Your current withdrawal rate: 4.94%
Spending gap not covered: $0.00

What each field means

Inputs

Retirement savings ($): The retirement savings used in the calculation, measured in $. Starts at 850000 $ so you have a working example on load.
Annual withdrawal in year one ($): The annual withdrawal in year one used in the calculation, measured in $. Starts at 42000 $ so you have a working example on load.
Other annual income ($): Social Security, pension, rental.
Annual spending target ($): The annual spending target used in the calculation, measured in $. Starts at 72000 $ so you have a working example on load.
Assumed annual return (%): The assumed annual return used in the calculation, measured in %. Starts at 6 % so you have a working example on load. Accepted range: -10–20 %.
Assumed inflation (%): The assumed inflation used in the calculation, measured in %. Starts at 2.7 % so you have a working example on load. Accepted range: 0–15 %.
Years you need it to last: The years you need it to last used in the calculation. Starts at 30 so you have a working example on load. Accepted range: 1–60.

Results

Years the portfolio lasts: Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Survives your horizon?: Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Ending balance: Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Max sustainable first-year withdrawal: Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
That as a withdrawal rate: Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
The 4% rule figure: Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Your current withdrawal rate: Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Spending gap not covered: Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.

FAQ

What is the 4% rule?

It comes from the Trinity Study: withdraw 4% of your portfolio in the first year of retirement, then increase that dollar amount with inflation each year. Across historical 30-year US windows, that pace rarely exhausted a balanced portfolio. It's a planning benchmark, not a guarantee.

How much can I safely withdraw in retirement?

It depends on your horizon, asset mix, and flexibility. Longer retirements and bond-heavy portfolios support less; a willingness to cut spending in down years supports more. Many planners now cite a range of roughly 3.3% to 4.5% rather than a single number.

What is sequence of returns risk?

The risk that poor market returns arrive early in retirement, while your balance is largest. Selling into a decline to fund withdrawals permanently shrinks the base. Holding one to three years of spending in cash or short bonds is the common defense.

Should I withdraw from taxable, traditional, or Roth accounts first?

The conventional order is taxable first, then traditional, then Roth — but blending is often better. Filling the low brackets with traditional withdrawals in your early retirement years reduces the RMDs that would otherwise force you into a higher bracket later.

Accuracy and limitations

Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.

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APA

RevenueLab. (2026). Retirement Withdrawal Calculator — How Long Your Money Lasts (2026). Retrieved from https://www.revenuelab.fyi/toolbox/retirement-withdrawal-calculator

HTML

<p>Source: <a href="https://www.revenuelab.fyi/toolbox/retirement-withdrawal-calculator" target="_blank" rel="noopener">Retirement Withdrawal Calculator — How Long Your Money Lasts (2026) — RevenueLab</a> (2026).</p>

Markdown

Source: [Retirement Withdrawal Calculator — How Long Your Money Lasts (2026) — RevenueLab](https://www.revenuelab.fyi/toolbox/retirement-withdrawal-calculator) (2026).