“How much do I need to retire?” is the question that stops people from starting. The number sounds enormous, nobody hands you a clean answer, so the whole thing gets pushed to “later.” But there is a real number for your life, and you can get close to it with grade-school arithmetic and two ideas.
Here’s the honest version: the target depends almost entirely on how much you’ll spend, not how much you earn. Two people on the same salary can need wildly different amounts, because one spends everything and the other spends half. So we start with spending.
Below: the two methods that turn your yearly costs into a savings target, a full worked example, and how to actually reach the number without guessing.
Start with spending, not income
Your retirement number is built on one input: what a year of retired life will cost you. Not your salary - your spending. A paid-off house, grown kids, and no commute can make retirement cheaper than your working years; more travel and healthcare can push it higher.
You don’t need a perfect figure. Start from your take-home pay today (our take-home pay calculator shows your real monthly net), subtract what stops in retirement (retirement contributions, payroll taxes on wages, a mortgage you’ll have paid off), and add what grows (healthcare, travel). That gives you a rough annual spending target - the one number everything else hangs on.
Method 1: the replacement-ratio shortcut
The fast, rough method: plan to replace 70% to 85% of your pre-retirement income each year. The logic is that once you stop working, you stop saving for retirement and stop paying payroll tax on wages, so you need less than your full salary to keep the same lifestyle.
Earning $80,000 a year? A common 80% target lands at about $64,000 a year in retirement. It’s a reasonable starting estimate when you don’t yet have a detailed budget. But it’s a shortcut, not the truth - a big spender might need 100%, a frugal saver 60%. Use it to get in the neighborhood, then sharpen with the next method.
Method 2: the 25x rule (the one to trust)
Here’s the method worth memorizing. Take the annual amount you’ll need from your own savings and multiply by 25. That’s your target nest egg.
Why 25? It’s the flip side of the 4% rule, a long-studied guideline that a retiree can withdraw about 4% of their savings in year one, adjust it for inflation each year after, and have a strong chance of the money lasting 30 years. If 4% is your first-year withdrawal, then your portfolio has to be 25 times that withdrawal - because 1 divided by 0.04 equals 25.
- Need $40,000 a year from savings? $40,000 x 25 = $1,000,000.
- Need $30,000 a year? $30,000 x 25 = $750,000.
- Need $60,000 a year? $60,000 x 25 = $1,500,000.
The 25x rule is more honest than the replacement shortcut because it’s built on spending, and it comes with real research behind it. It’s still a guideline, not a guarantee - more on its limits in our 4% rule guide.
Subtract what you won’t fund yourself
Your portfolio doesn’t have to cover your entire retirement budget. Other income fills part of the gap - and only the leftover needs the 25x treatment.
- Social Security. Most workers get a monthly benefit. Don’t guess the amount - your real estimate is on your Social Security statement at ssa.gov, based on your actual earnings record.
- A pension, if you’re one of the shrinking number of workers who has one.
- Any other steady income in retirement - rental income, a part-time plan, an annuity.
Add those up as an annual figure and subtract them from your yearly spending target. What’s left is the “gap” your savings must fill - and that gap, times 25, is your number.
The worked example
Let’s run one all the way through (illustrative numbers - use your own):
- Spending target. You earn $80,000 now. Using the 80% replacement guide, you estimate about $64,000 a year in retirement.
- Other income. Your Social Security statement projects roughly $28,000 a year in your case.
- The gap. $64,000 - $28,000 = $36,000 a year your own savings must cover.
- Apply 25x. $36,000 x 25 = $900,000. That’s your target nest egg.
Now, how hard is $900,000 to reach? That depends entirely on time. Say you’re 35, retiring at 65 - 30 years to invest. To grow to about $900,000 in 30 years at an illustrative 7% average annual return, you’d need to invest roughly $9,500 a year - about $800 a month.
Start the same plan 10 years later, at 45 with 20 years to go, and the identical $900,000 target needs about $22,000 a year - more than double the monthly amount, because compounding (your returns earning their own returns) has far less time to work. That gap between $800 and roughly $1,850 a month is the entire case for starting early. Play with your own numbers in the compound interest calculator.
How to actually hit the number
Knowing the target is half the job. Reaching it comes down to a few moves, roughly in order:
- Capture your full employer match first. If your job offers a 401(k) match, that’s an instant return no market can promise - claim all of it before anything else.
- Automate contributions so saving happens before you can spend the money. Payroll deductions into a 401(k) do this for you.
- Use tax-advantaged accounts - a 401(k), an IRA, or both - so more of your growth stays yours instead of going to tax.
- Raise the amount over time. Bumping your contribution by 1% of pay each raise is nearly painless and moves the target dramatically.
Model your own path - target, monthly amount, years, and how retirement accounts fit - with our retirement calculator.
What can break the estimate
This is a plan, not a promise. Be honest about what it assumes:
- Investment returns are not guaranteed. A 7% average is an illustration drawn from long historical periods; real markets swing, and some years lose money. Your actual result will differ.
- Inflation quietly raises the target. $64,000 of spending today costs more in 30 years. The 4% rule builds in yearly inflation raises on the withdrawal side, but the goal number itself grows too - revisit it every few years.
- Healthcare and long life are the wild cards. People are living longer, and medical costs rise faster than general inflation. A 30-year retirement horizon can stretch to 35 or 40.
- The 4% rule is debated. Some researchers argue for a more cautious 3% to 3.5% starting withdrawal today, which would push your multiplier from 25x toward 30x. Our 4% rule guide lays out both sides.
None of this means the exercise is pointless - the opposite. A rough target you revisit yearly beats a perfect one you never calculate. Get your number, start feeding it, and adjust as life clarifies.
Common mistakes with the number
Even people who run the 25x math correctly tend to trip on the same few things.
Forgetting taxes on withdrawals. Money in a traditional (pre-tax) 401(k) or IRA hasn’t been taxed yet, so when you withdraw it in retirement you owe ordinary income tax. That means to spend your $36,000 gap, you may need to withdraw somewhat more than $36,000 to cover the tax. The bite is usually smaller than people fear, because the standard deduction and low brackets shelter a chunk of it, often just a few thousand dollars of tax on a withdrawal that size, depending on your other income and state. Two ways to soften it: hold some savings in a Roth account, whose withdrawals are tax-free, and build a little extra into your gap number to cover tax on traditional-account money.
Counting your home in the number. Your house isn’t spendable retirement income, because you have to live somewhere. Home equity only becomes money you can spend if you downsize, sell and rent, or take a reverse mortgage, and each of those carries costs and trade-offs. Leave your home out of the 25x math and treat it as a separate backstop, not part of the nest egg your spending draws on.
Assuming your spending stays flat for 30 years. The simple 25x rule quietly assumes you’ll spend the same real amount every year of retirement. Research by David Blanchett found that real (inflation-adjusted) spending usually drifts down as people move from the active “go-go” years into slower ones, often enough that retirees need noticeably less than a flat projection suggests. That’s a pleasant surprise, and it softens the scary headline number. The counterweight is late-life healthcare and long-term care, which can push spending back up, so treat the flat figure as a reasonable middle estimate, not a fixed fact, and revisit it as your real life comes into focus.
FAQ
Is $1 million enough to retire?
It depends on your spending, not a headline figure. Using the 25x rule, $1 million supports about $40,000 a year from your portfolio (before Social Security or a pension). If your gap after other income is $40,000 or less, $1 million may be plenty; if it’s $70,000, it isn’t. Spending sets the answer.
Does the 25x rule include Social Security?
No - and that’s the point. You apply 25x only to the “gap” your own savings must fill after subtracting Social Security, a pension, and any other retirement income. That’s why the same person needs a smaller portfolio than their full spending would suggest.
What if I’m starting late?
Starting at 45 or 50 means less time for compounding, so you’ll need to save more per month, work a couple of extra years, or plan to spend a bit less - or some mix. It’s harder, not hopeless. Capture every employer match, max out tax-advantaged accounts, and run honest numbers in the retirement calculator.
Should I use 70% or 85% for the replacement ratio?
Use the replacement ratio only for a first rough pass, then switch to the spending-based 25x method, which is more reliable. If you must pick, lean higher (85%) if you plan an active, travel-heavy retirement, lower (70%) if you’ll have a paid-off home and a quiet lifestyle.
Sources
- William Bengen, “Determining Withdrawal Rates Using Historical Data,” Journal of Financial Planning (1994) - the research behind the 4% and 25x rules
- Social Security Administration - personalized benefit estimates at ssa.gov (used for your “other income” figure)
- David Blanchett, Morningstar research on the “retirement spending smile” - real (inflation-adjusted) spending tends to decline through much of retirement, so a flat projection can overstate the target; late-life healthcare is the counterweight
- Income, spending, and return figures above are illustrative; your target depends on your own numbers
- Investment returns are not guaranteed; a 7% average annual return is used only as an illustration
- Last reviewed July 3, 2026. This guide is general education, not personalized financial advice.
