Retirement Number (25x) Calculator
The retirement number is the size of nest egg you need to fund your spending without running out of money. This calculator uses the widely cited 25x rule: multiply your desired annual retirement spending by 25 to find your target portfolio. The rule is the mirror image of the 4 percent safe withdrawal guideline, because withdrawing 4 percent of a portfolio each year is the same as needing 25 times your annual spending. Enter the annual amount you expect to spend in retirement and, if you wish, a different withdrawal rate, and the tool returns your target retirement number and the implied first-year withdrawal. Seeing the target alongside the withdrawal makes the goal concrete and shows how spending less, or accepting a higher withdrawal rate, changes the number you must reach. The withdrawal rate is editable because the right figure depends on your time horizon, portfolio mix and risk tolerance; 4 percent is a starting point, not a promise. This is a planning estimate that ignores taxes, Social Security and changing spending, all of which you should weigh separately. Every figure here is computed deterministically from the formula shown in full below, with a worked example that reconciles exactly to the calculator so you can follow each step.
The 25x rule sets your target from your spending: retirement number = annual spending times 25 (a 4% withdrawal rate). For $60,000 of annual spending, the target is $1,500,000.00.
Retirement Number (25x) formula
Retirement number = Annual spending / withdrawal rate
At a 4% withdrawal rate this equals Annual spending x 25
Annual spending = the income you want each year in retirement
withdrawal rate = the share of the portfolio you draw yearly (4% = 0.04)
Dividing annual spending by a 4% withdrawal rate is identical to multiplying it by 25, which is why the rule is known as the 25x rule.
Worked example
Find the retirement number for 60,000 of annual spending at a 4% withdrawal rate.
- Apply the 25x rule: 60,000 x 25 = 1,500,000
- Or divide by the rate: 60,000 / 0.04 = 1,500,000
- Retirement number = 1,500,000.00
- First-year withdrawal: 1,500,000 x 4% = 60,000.00
These are the calculator's default inputs, so the result above matches the widget exactly.
Retirement Number (25x) Calculator: frequently asked questions
What is the 25x rule?
The 25x rule says your retirement target is 25 times your annual spending. It comes directly from the 4% withdrawal guideline: if you withdraw 4% of your portfolio each year, you need 25 times your yearly spending saved.
Where does the 4% rule come from?
The 4% figure draws on historical studies of how much a diversified portfolio could sustain over a long retirement without depleting. It is a rule of thumb, not a guarantee, and many planners adjust it for longer retirements or different markets.
Does this include Social Security?
No. The calculation targets spending funded entirely by your portfolio. If Social Security or a pension will cover part of your spending, subtract that income first and apply the rule only to the remaining amount you must self-fund.
Should I use a different withdrawal rate?
Possibly. A longer retirement or a more conservative outlook may call for a lower rate such as 3.5%, which raises the target. A shorter horizon might support a higher rate. The withdrawal rate is editable so you can test scenarios.
What is the retirement number formula?
Retirement number equals annual spending divided by the withdrawal rate, which at 4% is the same as annual spending times 25. For 60,000 of spending, the target is 1,500,000.00.
Official sources
- US retirement and benefits guidance: US Social Security Administration (SSA). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.