Will your retirement money last? Stress-test the 4% rule
The 4% rule says you can spend 4% of your savings in year one, raise that for prices every year, and the money should last 30 years. It is a rule of thumb, not a promise. This test runs 10,000 random retirements through your numbers and shows how many last, how many run out and when, and what changes the odds most. It runs in your browser, and nothing you type leaves it.
That is 4.00% of your money.
5 to 45
Slides in a straight line.
Advisor plus fund costs.
In 85 of 100 simulated retirements, $40,000 in year one (raised for prices each year) leaves money at age 95. In the other 15, the money ran out at a typical age of 93.
- Typical money left at 95, among those that last
- $399K
- in today's dollars
- Most you could spend in year one and still get 90 of 100
- Working...
- same stock mix, same markets
- Retirements that run out in the first 20 years
- 0 of 100
- Early failures are the ones a bad first decade causes.
Testing what-if changes...
Testing spending rates against retirement length...
How this works, and what it leaves out
- It runs 10,000 random retirements. Each year, stocks and bonds earn a random return built from the averages and ups and downs above.
- You take spending out at the start of each year. What is left earns the year's return, then any fee comes out.
- Spending rises with prices every year. The stock share slides in a straight line from your start to your end number.
- The same random markets are reused for every what-if row, so differences come from the change, not luck.
- It leaves out taxes, health shocks, home sales, and any year-to-year change in how much you want to spend. Social Security is optional and is treated as a flat amount raised with prices.
- Returns here are assumptions, not a forecast. Try lower stock returns in the assumptions box to see how much the answer depends on them.
Runs in your browser. Nothing you type is sent anywhere. Education only, not advice. Random seed 20261005, so the same inputs always give the same answer.
How to read your result
- Chance the money lasts. The share of 10,000 simulated retirements that still have money at the end. 90 or higher is comfortable for many people. Under 75 means a real risk.
- The dashed line. It shows what a calculator reports when it assumes the same return every year. It never runs out, which is why it can look safer than your result.
- The what-if rows. Each row changes one thing. Look for the biggest gaps. Fees, higher prices and a weak first decade usually move the answer the most.
- Cutting spending. That row always keeps money. Check how often spending had to fall and by how much before you count it as a fix.
Want the story behind the numbers? Read when the 4% rule works and when it fails. To compare this method with a real-history test, try why retirement calculators disagree.
Frequently asked questions
Does the 4% rule always work?
No. With a $1 million portfolio, $40,000 of first-year spending raised 3% a year, and a stock share that slides from 50% to 0% over 30 years, about 85 of 100 simulated retirements last. About 15 run out. A weak first decade, a 1% yearly fee or higher prices cut that number sharply.
What is the chance the money lasts?
It is the share of simulated retirements that still have money at the end. The test runs 10,000 random sequences of stock and bond returns built from the averages and ups and downs you set. It is a model, not a forecast.
What does sequence of returns mean?
It means the order of good and bad years. Two retirements can earn the same average return, but the one that has the bad years first can run out of money while the other ends with more than it started. Early losses hurt because you are also taking money out.
What spending rate gives better odds?
Lower first-year spending gives better odds. In the default plan, 3.5% lasts in about 96 of 100 retirements and 3% in about 99 of 100, while 5% lasts in about 41 of 100. The calculator shows the highest first-year spending that still gets 90 of 100.
Does this include taxes or Social Security?
It does not model taxes. Social Security or a pension is optional: enter a yearly amount in today's dollars and the year it starts, and the portfolio only covers the gap.
Education only, not advice. Results come from a model with the assumptions you set, not a forecast. It leaves out taxes, health shocks and changes in how much you want to spend. Past markets do not guarantee future results.