How Much Do I Need to Retire Calculator, Based on Spending

$1.46 million. That's how much Americans think they need to retire comfortably, according to Northwestern Mutual's 2026 Planning Progress Study (Harris Poll, 4,375 U.S. adults, January 2026). It's a striking figure. It also isn't your figure. If you searched for a "how much do I need to retire calculator," you want your own number, worked out from what you actually spend. This guide does that, and then shows why the honest answer comes back as a probability rather than one fixed target.

The short answer: start with spending, then multiply

Here's the rule most planners begin with. Take the yearly spending your savings have to cover and multiply it by 25. That's the 25x rule, and it's the flip side of the 4% rule. If you withdraw 4% a year, a portfolio of 25 times your spending pays for one year of it (NYSDCP).

The important words are your savings have to cover. That isn't your whole budget. It's what's left after Social Security, pensions and any other income.

There's also a newer wrinkle. Morningstar's research now puts the safe starting withdrawal rate at 3.9%, not 4%. "Safe" here means the money was still there in 90% of simulated outcomes over a 30-year retirement (Morningstar, The State of Retirement Income 2025, Dec 2025; see also Kiplinger's coverage). At 3.9%, the multiplier rises to about 25.6x.

How to work out your number in four steps

You don't need a spreadsheet. You need four figures.

1. Monthly spending in retirement. Use what you really spend, not a hopeful version. Multiply by 12.
2. Guaranteed income. Social Security, pensions, annuities. Subtract it from step 1 to get the gap.
3. A withdrawal rate. 4% is the classic choice. 3.9% follows Morningstar's latest work. A lower rate is more cautious.
4. Divide the gap by the rate. That's your target.

A worked example

These figures are made up to show the math. They don't describe anyone's real situation.

• Spending: $5,000 a month, so $60,000 a year
• Guaranteed income (say): $24,000 a year
• Gap the portfolio covers: $36,000 a year

Look at how fast it climbs. Going from 4% down to 3% adds $300,000 to the target in this example. Small changes to the withdrawal rate make a big difference, and most calculators skip right past them.

Why the rules of thumb don't agree

Search this topic and you'll find 10x your salary, 11x your final pay and 25x your spending, often on the same page. Nobody explains why they differ. Here's why.

10x salary (Fidelity's milestone). Fidelity's guideline is 1x your salary by 30, 3x by 40, 6x by 50, 8x by 60 and 10x by 67. The model assumes a 15% savings rate, a plan lasting to age 93 and 90% confidence. The key detail: it only aims for savings to replace about 45% of your income. It expects Social Security to cover the rest (Experian).

25x spending. This one assumes your portfolio pays for the spending you plug in. Plug in your whole budget and you're assuming no other income. Plug in only the gap, as in the example above, and it lines up with the salary-based rules.

80% income replacement. This is another common guideline (Rethinking65). It's a shortcut for the spending figure in step 1 when you don't know your real spending yet.

So the rules aren't really contradicting each other. They answer different questions. The spending-based approach is the one you can check against your own bank statements, which is why we build around it.

How Much Do I Need to Retire Calculator: why one number isn't enough

Most popular calculators give you one deterministic answer. You enter age, savings, returns and inflation, and you get a single target and a monthly savings figure. Kiplinger's well-known retirement savings calculator works this way, and Kiplinger says itself that the result only gives you "an idea" of what you'll need.

That's honest, and it points to the real problem. An average-return projection assumes markets deliver the average every year. They don't. Two retirees with the same savings and the same long-run average return can end up in very different places, depending on when the bad years arrive.

What Monte Carlo means, in plain English

A Monte Carlo simulation doesn't assume one future. It runs your plan through many possible ones. Some start with a crash, some with a boom, and some are just mediocre for a decade. Then it counts how many of those futures still have money in the account at the end.

That count is your success rate. If 900 of 1,000 futures stay funded, your plan succeeds 90% of the time. That's the same standard Morningstar used to land on 3.9%.

A success rate is more useful than a single target for a few reasons:

• It tells you how much room you have. A plan at 95% has more cushion than one at 75%. A single target can't show you that difference.
• It makes trade-offs visible. Retire a year later, trim spending a bit, or add part-time income, and you can watch the odds move.
• It's candid. No calculator knows the future. A probability says so out loud.

This is how Monte Climb works. You enter three numbers: your age, what you've saved for retirement, and what you spend each month. We run them through 1,000 simulated futures and show you how many stay funded. It's a probability, not a promise.

Three risks your number needs to price in

A target that ignores these is a guess.

1. Living longer than you planned

About one in three 65-year-olds may live to at least 90, according to the Social Security Administration (Retirement Information for Medicare Beneficiaries, 2026). A plan that ends at 85 is quietly betting against a third of retirees. That's why the plan you build here runs to age 95 by default, and you can extend it.

2. Health care

Fidelity estimates a 65-year-old retiring in 2025 will spend $172,500 on Medicare premiums, deductibles and prescriptions over retirement. That figure leaves out long-term care entirely (Fidelity Investments, 2025 Retiree Health Care Cost Estimate, Jul 2025). It's a line item, not a rounding error. Our engine charges Medicare premiums and income-based surcharges year by year rather than using one flat guess.

3. Bad years early on

This is called sequence-of-returns risk. A market drop in your first few years of withdrawals does more damage than the same drop later, because you're selling investments while prices are low. Averages hide this. Simulations show it.

You're not alone if you've never done this

Here's the reassuring part. EBRI's 2025 Retirement Confidence Survey found that 48% of workers have never estimated how much monthly income they'll need in retirement (EBRI/Greenwald, Fact Sheet 3). Nearly half are guessing.

Many people are worried about this. In Northwestern Mutual's 2026 study, 46% of Americans said they don't expect to be financially prepared, and 48% think they may outlive their savings. The same study found 41% work or plan to work in retirement. That matters, because even modest part-time income shrinks the gap your savings have to cover, and that lowers your target.

Worry doesn't change your odds. Data can help you see them. Your monthly spending is the first step.

Turning your number into a decision

Once you have a target and a success rate, the useful questions follow:

• Am I on track? Compare what you've saved with the target, and check the odds.
• Can I retire at 62? Fewer working years and more years of withdrawals. See how the success rate shifts.
• What can I safely spend? Work backward from the success rate you're comfortable with.

You can ask William, our AI planner, any of these. He shows his work, and you can talk to him the way you'd talk to a friend. Keep in mind that this is planning software, not financial advice. It helps you see your odds clearly, and the decisions stay yours.

Run your own numbers

Three numbers. Your age, your savings, your monthly spending. The calculator runs in your browser, and nothing is saved until you say so.

Show my answer →

If you'd like to go further, Monte Climb offers a 7-day trial of the full planning app for $1. It's built on the same engine and includes William.

Frequently asked questions

How much do I need to retire based on my spending?

A common starting point is to multiply the yearly spending your savings must cover (after Social Security and pensions) by 25, which matches a 4% withdrawal rate. Using Morningstar's 3.9% safe starting withdrawal rate raises the multiplier to roughly 25.6x.

Is the 4% rule still safe?

Morningstar's research now puts the safe starting withdrawal rate at 3.9%. Its test was whether money lasted in 90% of simulated outcomes over a 30-year retirement. That's slightly below the classic 4%, so targets built on 4% may be a little optimistic.

Why do retirement rules of thumb like 10x salary and 25x spending disagree?

They measure different things. Fidelity's 10x-salary-by-67 milestone aims to replace about 45% of income from savings and assumes Social Security covers the rest. The 25x rule assumes your portfolio pays for whatever spending you plug in, so it only lines up with the salary rules if you use the gap left after other income.

What is a Monte Carlo retirement calculator?

It runs your savings and spending through many simulated market futures instead of one average return, then reports the share of futures where your money lasts. For example, 900 funded futures out of 1,000 is a 90% success rate.

How long should a retirement plan last?

The Social Security Administration notes that about one in three 65-year-olds may live to at least 90. That's why many planners run plans well past 85. Monte Climb's plans default to age 95, and you can extend them.