Sequence of Returns Risk Calculator: When Bad Years Come First

Same returns. Same average. Opposite order. A $1 million portfolio held entirely in the S&P 500 from 1989 to 2008 averaged 8.43% a year and grew to about $3.1 million. Run those exact returns in reverse and the same portfolio finished with about $235,000, according to a BizTimes analysis of sequence risk. The article notes that this is an extreme, all-stock example. Still, the lesson holds up. When you're living off a portfolio, the order of returns can matter as much as the average. A sequence of returns risk calculator tests one thing: if the bad years come first, does your plan still work?

The short version: order barely matters while you're only saving. It matters a lot once you start withdrawing. And research suggests the damage comes mostly from a weak first decade of retirement, not from one bad first year.

Below, we cover what these calculators measure, the main types, and how to read your result.

What a sequence of returns risk calculator actually tells you

Every version of this tool tries to answer the same question. How much worse off are you if the downturn arrives early in retirement instead of late?

They do it in different ways:

• Ending balance. Your money if good years come first, compared with your money if bad years come first.
• Survival rate. The share of simulated or historical periods in which your money lasts.
• Safe withdrawal rate. The highest starting withdrawal that survives a chosen share of scenarios.

The first type is the most vivid. The second and third are more useful for an actual decision, because they don't depend on one invented sequence of years.

Why order only matters once you start withdrawing

If you never add or remove money, a portfolio's final value is the same in any order of returns. Multiplication doesn't care about sequence.

Withdrawals change that. When markets drop early and you're still selling to pay for groceries and Medicare premiums, you sell more shares at low prices. Those shares are gone. They aren't around when the recovery comes. The calculate.co.nz sequence of returns risk calculator puts it plainly: a slump early on leaves fewer units to recover later. Its own worked example shows a $180,000 gap between the bad-first and good-first orderings.

Here's another illustration. Wealthvieu describes two hypothetical retirees. Both average 5% a year and both withdraw $50,000 a year. The one with the bad sequence ends about $665,000 lower. Those figures are illustrative, not historical, but the pattern is real.

It's the first decade, not the first year

You might assume a crash in year one is the worst thing that can happen. The research says otherwise.

Michael Kitces looked at historical safe withdrawal rates and found "remarkably little relationship" between returns in the first year or two of retirement and the withdrawal rate that turned out to be sustainable. What predicted trouble was returns across the first decade. In his words: "It's the story of the bad decade." (Kitces, Understanding Sequence of Return Risk)

A sharp crash followed by a quick rebound can be survivable. A long, flat, grinding decade while you keep withdrawing is the harder case.

Kitces also points out that high nominal returns often come with high inflation. That's why a good calculator should work in real, inflation-adjusted terms. A decade of decent headline returns can still leave you behind if prices rose faster.

Take a real example. In Morningstar's illustration of someone retiring in 2000, the portfolio was nearly cut in half by the end of year three. It never fully recovered and was worth about $644,000 by age 85. One bad year didn't cause that. A bad stretch did, at the worst possible time.

The three kinds of calculator

Most tools fall into one of three groups. Each answers a slightly different question.

Monte Carlo sounds technical, but the idea is simple. Instead of assuming one average return every year, the software generates many possible futures. Some start badly, some start well, most land in between. Then it counts how many of those futures leave you with money at the end.

That makes Monte Carlo a natural sequence of returns risk calculator. Every simulated path has its own ordering of good and bad years, so sequence risk is built into the result. You don't have to add it separately.

One caution. Coastiq argues that many tools sold as "Monte Carlo" just add random noise to a constant return. It's worth knowing what's behind the number you're given.

What to look for before you trust the answer

A calculator can be precise and still wrong if it leaves out the things that sink real retirements. Check for these:

1. A probability, not a single projection. "You'll have $1.2 million at 85" based on an average return hides sequence risk completely. A success rate shows it.
2. A long enough horizon. About one in three 65-year-olds may live to 90 or beyond (Social Security Administration, Retirement Information for Medicare Beneficiaries, 2026). A plan that stops at 85 quietly bets against a third of retirees.
3. Real health care costs. Fidelity estimates $172,500 in Medicare premiums, deductibles and prescriptions over retirement for a 65-year-old retiring in 2025, and that figure excludes long-term care (Fidelity Investments, 2025 Retiree Health Care Cost Estimate, July 2025). These costs keep coming in down markets too, which makes early losses hurt more.
4. Inflation-adjusted results. Per Kitces, a "good" nominal decade can be a bad real one.
5. Honest method notes. You should be able to tell whether returns are drawn from history, generated randomly, or just smoothed.

How to read your result

Say a calculator tells you 85% of futures stay funded. What does that mean?

It means that in 15% of simulated futures, the money ran out before the end of the plan. Many of those are probably the futures where the first decade went badly. It doesn't mean you have an 85% chance of being fine and a 15% chance of disaster. It's a measure of how much room your plan has, given what you've entered.

For reference, Morningstar's 2025 research puts the safe starting withdrawal rate at 3.9% for a 30-year retirement. That figure is judged by whether money remains in 90% of simulated outcomes, not by an average return (Morningstar, The State of Retirement Income 2025, December 2025). Those are the same terms a Monte Carlo test uses for your own numbers.

It's a probability, not a promise.

What people do about sequence risk

The research covers several common responses. These are general ideas, not recommendations for your situation:

• Flexible spending ("guardrails"). Spending less in bad years so you sell fewer shares at low prices.
• A cash or bond buffer. Keeping a few years of spending outside stocks so you aren't forced to sell during a slump.
• A bond tent. Holding more bonds around your retirement date, when sequence risk peaks, then shifting gradually back toward stocks.
• Delaying Social Security. A larger guaranteed income later can reduce how much the portfolio needs to supply.

Each one has trade-offs. Whether any of them fits you depends on your own numbers, which is exactly why it helps to see those numbers as odds.

Run your own numbers

Most people haven't done even the first step. EBRI's 2025 Retirement Confidence Survey found only 52% of workers have estimated the monthly income they'll need in retirement (EBRI/Greenwald, Retirement Confidence Survey 2025, Fact Sheet 3).

The Monte Climb retirement calculator starts with three numbers: your age, your retirement savings and your monthly spending. It runs them through 1,000 simulated futures, each with its own order of good and bad years, and tells you how many stay funded. Plans run to age 95 by default, and you can push that further. The engine charges Medicare premiums and income-based surcharges year by year instead of using a flat guess. It runs in your browser, and nothing is saved until you choose to save it.

If the number raises questions, you can ask William, our AI planner. Try "Am I on track?", "Can I retire at 62?" or "What's a sustainable spend?" He shows his work. It's planning software, not advice.

Three numbers. One clear answer. Show my answer →

Frequently asked questions

What is sequence of returns risk?

It's the risk that poor market returns arrive early in retirement, while you're withdrawing money. Selling investments at low prices to fund spending leaves fewer shares to recover later, so two retirees with the same average return can end up far apart depending on the order those returns arrived in.

Does sequence of returns risk matter while I'm still saving?

Much less. With no money going in or out, the order of returns doesn't change the final balance. The risk becomes significant once you start taking regular withdrawals, which is why the years just before and after retirement get the most attention.

Is a bad first year or a bad first decade more dangerous?

Research by Michael Kitces found remarkably little relationship between returns in the first year or two of retirement and the sustainable withdrawal rate. Returns over the first decade, especially after inflation, were the stronger driver.

Is a Monte Carlo calculator better than a historical backtest for sequence risk?

They answer different questions. Historical backtests replay real past periods, including actual crashes and inflation shocks, but there are only a limited number of them. Monte Carlo simulations generate many randomized return paths and give you a probability of success. Many planners look at both.

Can a sequence of returns risk calculator tell me how much I can safely spend?

It can show you the odds that a given spending level lasts. Morningstar's 2025 research, for example, puts the safe starting withdrawal rate at 3.9% for a 30-year retirement, based on money lasting in 90% of simulated outcomes. Any result is a probability, not a guarantee, and it isn't personalized financial advice.