How Long Will My Money Last?

A calculator that draws one smooth line at 7% can make the money look like it lasts. That line is one path: the return you typed, every year, in the same order. Real years do not arrive that way. If you are withdrawing and a crash shows up early, you sell more shares at low prices. The runway shortens even if the average return over 40 years still prints as 7%.

This article walks through that distinction, then opens a labeled hypothetical — Retired at 52 — so you can see a 40-year, ~5.5% spending plan on a timeline instead of in a slogan. It is not advice. It is not a recommendation to spend 5.5%. The sample spends faster than 4% on a 40-year clock. That is the point of opening it.

The sibling question — how large a stash you need in the first place — lives in What Is My FIRE Number?. This page is the inverse: given what you have, how long does the spending last?

Runway Is Spending Versus the Pile

Runway is how many years the portfolio can fund living expenses before it hits a floor you care about — zero, or some leftover you chose as a goal.

Two knobs dominate:

1. How much you take out. Monthly spending is the withdrawal. Annual spending divided by starting portfolio is the starting withdrawal rate.
2. What you assume the leftover earns. Each account can have its own expected return. The main chart applies those rates in a straight line, year after year.

Inflation is a third knob if you want the later years in today's dollars. Debts, one-time events, and a later transfer between accounts all change the path. None of that requires a new engine. It requires numbers you actually have.

A FIRE number asks "how much do I need?" Runway asks "how long will this last?" They use the same identity written backwards: starting withdrawal rate = annual spending ÷ portfolio. At 4%, that is the 25x rule. At 3.5%, about 28.6x. See 4% vs 3.5% SWR for Early Retirees for the horizon behind those rates. This article stays on the spending side of the same math.

Starting Withdrawal Rate, in Plain Numbers

Take the live sample as arithmetic, not as a plan you should copy.

• Portfolio: $1,240,000
• Living expenses: $5,500/month from the brokerage (no paycheck) = $66,000/year
• Starting withdrawal: $66,000 ÷ $1,240,000 ≈ 5.3%, which the site rounds as ~5.5%

Starting withdrawal	Annual spending on $1.24M	Versus this sample's $66,000	Horizon people usually attach to it
4%	$49,600	$16,400/year less spending	~30-year research (Bengen 1994)
3.5%	$43,400	$22,600/year less spending	40–50 year FIRE, same paper
~5.3% (this sample)	$66,000	—	40-year clock in the example

The 4% rule of thumb is a starting rate from research on roughly 30-year retirements, not a 40-year guarantee. For 40–50 year FIRE, that same 1994 paper sat closer to 3–3.5%. The FIRE calculator turns a rate into a stash size. It does not prove the rate will last.

This sample spends faster than 4% on a 40-year clock. Open it to see what that looks like on a timeline. Do not open it because 5.5% is "the number."

Why a Single Average Return Lies

The year-by-year chart on this site is a linear projection: the expected returns you entered, applied every year. If stocks are set to 7%, the line uses 7%, then 7%, then 7%. It is easy to read. It is also tidy in a way real years are not.

Average return is a summary of the whole stretch. It does not tell you whether the weak years clustered at the start, the middle, or the end.

While you are still saving, order matters less. A down year means you buy more shares at lower prices.

Retirement flips that. Each year you need cash. If prices are down, you sell more shares to raise the same dollars. Those shares do not get the recovery. Later growth compounds on a smaller pile. Two people can share the same starting balance, the same spending, and the same average return, and finish far apart. The one who withdrew through an early crash sold more of the portfolio when it was cheap.

That is sequence of returns risk. A smooth 7% line can look like the money lasts. Early withdrawals in a crash shorten the runway.

This page will not re-explain the whole mechanism. The walkthrough — including a year 1 vs year 5 vs year 10 sketch — is in Sequence of Returns: Why a Crash in Year 1 Hits Harder Than Year 5 or Year 10. The overlay itself is the Sequence of Returns Calculator: one crash size you choose, in one year you choose, compared with the undistorted baseline. It is not a replay of historical market years.

Monte Carlo on this site is a different, related question: many random paths instead of one line. It draws Gaussian (Box–Muller) returns around the expected returns you enter, 100–1,000 runs, then shows percentile bands and the share of paths that still have money. It is not historical backtesting, and it is not "thousands" of runs. Use it when you want a cloud of outcomes. Use the sequence tool when you want one explicit crash in year 1, 5, or 10. The method split is in Parametric vs Historical Monte Carlo.

Flag on the sample below: the Retired at 52 chart is a linear projection with assumed returns. It is not a guarantee the nest egg lasts 40 years. Sequence risk is why the average can lie.

A Hypothetical: Retired at 52

This is a labeled example on the site, not a person, not a recommendation, and not a tax plan.

Name: Retired at 52
On-site description: "Just retired — will the nest egg last 40 years at ~5.5% spending?" / "No paycheck — will $5,500/mo spending last 40 years?"
Horizon: 40 years
Goal in the sample: Portfolio Lasts 40 Years, with $100,000 remaining in year 40

What's in the sample (use only these numbers)

Account	Balance	Assumed return (input, not a forecast)
IRA/401(k), stocks	$500,000	7%
Taxable brokerage, stocks	$340,000	7%
Bond index	$360,000	4%
HYSA	$40,000	4.5%
Total	$1,240,000	—

Cash flow in the sample:

• Living expenses: $5,500/month from the brokerage. No paycheck.
• IRA/401(k) → brokerage: $5,500/month starting in year 8 (current year + 8). The sample simply delays that transfer. It does not model taxes, penalties, RMDs, or a claiming strategy. Do not read a tax story into the lag.
• No Social Security in the sample.
• No tax modeling in the sample, or on this site.

$5,500/month is $66,000/year. Against $1,240,000 that is about 5.3% in year one (~5.5% as labeled). A 4% start on the same pile would be $49,600/year. A 3.5% start would be $43,400. The sample is the more aggressive of those on purpose, on a 40-year clock, with a leftover goal of $100,000 — not $0, and not "the money lasts forever."

The returns above are what you (or the sample) typed. Stocks at 7%, bonds at 4%, HYSA at 4.5% are planning assumptions. They are not a market forecast and not a promise. Change them and the line moves.

Open the live plan, then change spending, returns, or the crash year. The hypothetical is useful because the numbers are filled in. It is not useful as a template for your life.

Open the Retired at 52 sample

Common Mistakes

Mistake 1: Trusting the smooth 7% line

A straight-line projection can show the portfolio still standing in year 40. That is the path where every year earned the rate you typed. It is one path. If year 1 is a crash and you keep spending $5,500/month, you sold extra shares at the low. The average over 40 years can still look fine while the runway is already shorter. Run the sequence stress test on the same plan before you treat the line as the answer.

Mistake 2: Treating 4% as a 40-year law

4% (25x expenses) is the 30-year line from Bengen's 1994 paper, later turned into a slogan. Early retirees often need 40–50 years. That paper's longer-horizon discussion sat around 3–3.5%. This sample starts near 5.3% for 40 years. That is not "the 4% rule with a little extra." It is a faster spend, on a longer clock, which is why you should look at it rather than round it to a slogan. Details: 4% vs 3.5% SWR for Early Retirees.

Mistake 3: Confusing a FIRE number with runway

A FIRE number says how large a stash a chosen withdrawal rate implies. Runway says how long this stash lasts at this spending. Hitting 25x (or 28.6x) does not mean the money lasts forever. A portfolio can be "the number" and still fail if early returns are poor and withdrawals stay fixed. Size the number on one page; watch the years on the other. What is my FIRE number?

Mistake 4: Adding income the plan does not have

This sample has no paycheck and no Social Security. Putting SS, a pension, or a part-time bridge into your projection is a different scenario. Do not mentally add them to Retired at 52 and then conclude the ~5.5% spend is conservative. The calculator will not invent a benefit you did not enter.

Mistake 5: Reading a linear result as a guarantee

The sample's goal is $100,000 left in year 40. Whether the straight-line chart meets that goal depends on the returns you leave in place. Meeting a goal on a linear projection is not insurance. Sequence risk is still there. Monte Carlo (100–1,000 Gaussian paths around your expected returns) shows a range, not a verdict. Neither tool is a paid financial plan.

Mistake 6: Mixing up this site's tests with historical replay

The sequence tool is a crash you place in a year you pick. Monte Carlo here is parametric — Gaussian draws around your inputs, 100–1,000 runs — not FIRECalc-style replay of past U.S. market years, and not "thousands" of simulations. If the question is "what if I had retired in 1966?", that is a different class of software. We do not do that. We also do not model taxes, Roth conversions, or Social Security claiming.

How to See How Long Your Money Lasts

Use the Net Worth Projection Calculator for a blank year-by-year timeline, or start from the filled-in Retired at 52 sample and replace the numbers with yours.

1. Add assets (and debts, if you have them). Give each account its own expected return. The sample uses stocks at 7%, a bond index at 4%, and an HYSA at 4.5%. Those are inputs, not defaults you must keep.
2. Add living expenses as a recurring withdrawal. Monthly or yearly. Name the account the cash comes from. The sample spends $5,500/month from brokerage with no paycheck.
3. Add other events only if they are real in your plan. Transfers, a later withdrawal from a different account, a one-time expense. The sample delays an IRA/401(k) → brokerage transfer until year 8. Do not add Social Security or tax events the tool cannot model.
4. Set the horizon. The calculator projects 1–60 years. Retired at 52 is set to 40. Match the years you actually need to fund, not a slogan.
5. Set inflation if you want later years in today's dollars.
6. Set a goal if you have one. The sample's goal is $100,000 remaining in year 40 — "the portfolio lasts," not "the portfolio is unchanged."
7. Read the year-by-year table, not just the ending headline. Export CSV/Excel if you want it in a spreadsheet. Share a link if you want the same scenario back later. No signup required for the core tool; numbers stay in the browser by default.
8. Break the straight line on purpose. Same plan, sequence of returns: crash in year 1, then the same crash in year 5, then year 10. Then, if you want a cloud instead of one shock, Monte Carlo at 100–1,000 runs around the returns you entered.

Keep spending constant while you change one thing — the crash year, the return assumption, or the withdrawal. If the runway only looks long on the smooth line, you have the answer the average was hiding.

Frequently Asked Questions

How long will my money last in retirement?

As long as withdrawals, in the order they happen, do not drain the portfolio before your horizon. Divide annual spending by the starting portfolio to get the starting withdrawal rate. Then project those withdrawals against the returns you assume, for the number of years you need. A single average return is not the full answer, because an early crash while you are selling shortens the runway. Use the net worth projection for the straight line, then the sequence calculator for a crash in year 1 vs 5 vs 10.

How do I calculate how long my savings will last?

Enter each account and its expected return, add monthly or annual spending as a withdrawal, set a 1–60 year horizon and inflation if you want it, and read the year-by-year net worth table. That is the linear runway. Optionally set a leftover goal (the sample uses $100,000 in year 40). Then stress-test. There is no honest one-number formula that skips the path.

Will a smooth 7% projection tell me if the money lasts?

No. It tells you what happens if every year earns the rate you typed. That can look like 40 years of runway. Early withdrawals in a crash sell extra shares at low prices; later 7% years cannot act on shares you already sold. The average can still print as 7%. See why a crash in year 1 hits harder than year 5 or 10.

Is ~5.5% a recommended withdrawal rate for 40 years?

No. The Retired at 52 sample spends $66,000/year from $1,240,000, which is about 5.3% (~5.5% as labeled) on a 40-year clock. That is faster than 4%, and faster than the 3–3.5% band often used for 40–50 year FIRE. The sample exists so you can see an aggressive spend on a long horizon — not so you copy it. Test 4% and 3.5% on the same expenses with the FIRE calculator.

Does this include Social Security, taxes, or Medicare?

No. The sample has no Social Security. This site does not model taxes, Roth conversions, Social Security claiming, or Medicare. If those cash flows matter in your life, they are outside this tool. Do not add them in your head to the sample and then trust the line.

What is the Retired at 52 sample, exactly?

A hypothetical: $1,240,000 across an IRA/401(k) ($500,000 at 7%), taxable brokerage ($340,000 at 7%), bond index ($360,000 at 4%), and HYSA ($40,000 at 4.5%); $5,500/month spending from brokerage; an IRA/401(k) transfer to brokerage starting in year 8; 40-year projection; goal of $100,000 left in year 40. No paycheck. No Social Security. No tax modeling. Linear returns as entered — not a guarantee.

How is this different from a FIRE number?

A FIRE number is the stash a withdrawal rate implies (25x at 4%, about 28.6x at 3.5%). Runway is how many years the stash you already have lasts at the spending you actually do. Same identity, opposite direction. What is my FIRE number?

The Bottom Line

"How long will my money last?" is spending versus portfolio, over a real number of years.

• The starting withdrawal rate is annual spending divided by the pile. The live sample is $66,000 ÷ $1,240,000 ≈ 5.3% (~5.5%), for 40 years, with a $100,000 leftover goal. That is faster than 4% on a long clock. Look at it. Do not copy it as a rule.
• The year-by-year chart is a linear projection with the returns you typed. A smooth 7% line can look like the money lasts.
• Sequence of returns is why that average can lie. Early withdrawals in a crash shorten the runway. Same crash later usually does less lasting damage. Stress year 1, then year 5, then year 10.
• 4% vs 3.5% is the starting-rate conversation for horizon. 4% was a ~30-year finding. 40-year FIRE often starts lower. A sample at ~5.5% is not that conversation's conclusion.

Run the numbers on a timeline you can export and share. Then break the straight line on purpose. The calculator does not know what you should want. It can show you how long this spending lasts under these assumptions — and how fast that answer moves when year 1 is ugly.

Project your net worth year by year · Open Retired at 52