Run your plan against the four scenarios that actually kill retirements: a bear market sequence, a long life, a medical event, and a forced early retirement. See pass or fail for each, year by year.
Let's lay it out on the table, man. Most retirement calculators out there are built to make you feel okay, not to tell you the truth. They assume you'll die at 85. They assume the market delivers a smooth 7 percent every year. They quietly ignore state tax on Social Security. And they only ever run one scenario: the optimistic one.
That's the Longevity Turd. The grumpy little advisor who looks at you at 50 with $500,000 in savings, averages his rosy return, rounds your lifespan down to what the actuary tables said in 1980, and says "you're fine." He forgets that roughly one in ten of today's 65-year-olds will reach 95. He forgets that a 2008-style market drop in your first five years of retirement can shave a decade off your runway even if the long-term average stays the same. He forgets that Medicare doesn't cover long-term care, and a single stay in memory care can run $100,000 in a year.
FigureNerd doesn't do rosy. FigureNerd runs your plan against the four scenarios that actually kill retirements, plus a worst-case combined run where all three big ones hit at the same time. You get pass or fail for each, traffic-light style, so you know which levers to pull before you stop working, not after.
Stress-test the plan. Then decide what to change.
Retirement researchers have studied thousands of plans that failed. Four root causes show up over and over. Any one of them, alone, can turn a comfortable plan into a tight one. Two or three together is how the truly painful outcomes happen.
Two retirees with the exact same 7 percent average return over 30 years can end up with wildly different outcomes if one hit a bear market in year one versus year twenty. Early losses are devastating because the retiree is withdrawing from a shrinking balance. The subsequent recovery cannot fully repair the damage because the shares that were sold to fund early spending are gone. A 25 to 35 percent drawdown in the first five years of retirement can shave 8 to 12 years off the runway.
The Social Security Administration's actuarial tables give a 65-year-old man a life expectancy of about 19 more years and a 65-year-old woman about 22. But those are averages. Roughly one in four 65-year-olds will reach 90. Roughly one in ten will reach 95. For a married couple, the odds that at least one spouse reaches 95 climb above 25 percent. A plan that ends at 85 and a person who doesn't end at 85 is the definition of a retirement crisis.
Medicare covers a lot, but not everything. The big gap is long-term care: nursing home, memory care, extended in-home care. Genworth's annual cost-of-care survey puts the 2024-2025 national median for a private nursing-home room around $127,000 per year. Memory care averages roughly $85,000 to $100,000. Home health aides run $6,000 to $7,500 a month. Medicare covers up to 100 days of skilled nursing after a hospital stay, but custodial care (which is the majority of long-term care) is on you, unless you have long-term-care insurance or you spend down to Medicaid.
The Employee Benefit Research Institute has tracked this for decades: the actual retirement age is typically 3 to 5 years earlier than the target retirement age. Health events, layoffs, caring for a parent or spouse, and company restructuring all force the hand. Retiring at 62 instead of 65 means three fewer years of contributions, three fewer years of compounding, three more years to fund, and a permanent 30 percent reduction in Social Security if you claim at 62 instead of 67.
We show our work so you can trust the output. Here is the order of operations the stress test runs, using 2026 assumptions.
Where we simplify: this calculator runs five discrete scenarios, not a full Monte Carlo. Monte Carlo tools (Empower, NewRetirement, portfolio-visualizer) run 1,000+ random-return paths and give you a probability distribution. That's a more complete picture, but harder to read at a glance. The FigureNerd approach gives you five clearly labeled survival checks you can remember and act on.
If the stress test above came back red on one or more scenarios, the plan isn't broken. It just means the current inputs don't survive a bad draw. Three moves close most of the gap, in descending order of leverage.
Every extra $500 a month saved for 15 years at 6 percent return adds about $145,000 to your nest egg. Look for hidden capacity: the employer 401(k) match you're not fully capturing, the Roth IRA contribution you're skipping ($7,000 in 2026 if you're under 50, $8,000 if you're 50-plus), the catch-up contribution in a 401(k) ($7,500 extra for 50-plus, up to $11,250 for ages 60 to 63 starting 2026 under Secure 2.0). If retirement is less than 10 years out, saving more has limited time to compound, and the other two levers matter more.
Delaying retirement from 65 to 67 does three things at once: two more contribution years, two more years of compounding, two fewer years of retirement to fund. Combined impact on a typical plan: 15 to 20 percent more runway. Delaying to 70 is more like 35 to 45 percent, because Social Security also gets permanently bigger. Every year you delay SS between full retirement age (67 for most people born after 1960) and 70 adds roughly 8 percent to the benefit, permanently, inflation-adjusted. Claiming at 70 instead of 62 is a permanent 77 percent larger check. For most healthy retirees, this is the closest thing to a free lunch in retirement planning.
Dropping target spending from $70,000 to $62,000 per year lowers the nest egg needed by about 11 percent. Most of the "spend less" opportunity lives in housing (downsize, pay off mortgage, move) and healthcare (Medicare Advantage vs Medigap trade-offs). If you're in one of the ten states that still tax Social Security (Colorado, Connecticut, Kansas, Minnesota, Montana, New Mexico, Rhode Island, Utah, Vermont, West Virginia), moving to a no-SS-tax state can save $1,500 to $3,000 per year on the tax alone, plus a potentially lower cost of living. Over a 25-year retirement, that's $37,500 to $75,000 of buying power recovered.
The calculator up top shows you which scenarios fail. The three levers above tell you how to close the gap. Pick the one that fits your life. Pulling any one of them, consistently, is what turns a red scenario into a yellow one, and a yellow into green. That's the difference between hoping and planning.
Meet John and Susan. Both 65 in January 2008. Retired right on target after 40 years of steady saving. $1,200,000 combined in a 60/40 portfolio. Target spending around $65,000 a year. Social Security and a small pension covered $34,000 of that. The remaining $31,000 came from a 4 percent withdrawal from the portfolio. On paper, the plan cleared 35 years of runway with margin to spare. The retirement planner had told them the math worked. The math did work, in the scenarios the planner ran.
February to October 2008: the S&P 500 fell 37 percent. A 60/40 portfolio fell roughly 24 percent. John and Susan's $1,200,000 became $912,000 by year-end. They kept withdrawing the same $31,000 inflation-adjusted that they planned, because that's what the 4 percent rule told them to do. By the end of 2009, after continued withdrawals and a partial recovery, the portfolio was around $890,000. Then came a good decade (2010 through 2019). Then COVID. Then the 2022 drawdown. Then a partial recovery. Then the 2028 downturn (hypothetical in this story).
By 2038, at age 95, John and Susan had $0 in the portfolio. They were still alive. Their Social Security and pension still arrived every month. But the lifestyle they'd budgeted for was no longer sustainable. They moved in with their daughter.
Here is the part that hurts. If the same exact 30 years of annual returns had been reversed, with the good decade first and the 2008 drop at age 95 instead of 65, the portfolio would have had roughly $1.6 million at age 95 instead of zero. Same returns, different order. That's sequence-of-returns risk in a single sentence.
What John and Susan could have done differently: held 2 to 3 years of spending in cash or short-term bonds as a "bear market buffer," so they wouldn't have had to sell equities at the bottom. Used a dynamic withdrawal rule (Guyton-Klinger guardrails) that would have cut spending modestly in 2008 to 2009, preserving more shares for the recovery. Delayed claiming Social Security until 70 to lock in a permanently higher floor of guaranteed income. Any one of those moves, applied in 2008 and 2009, would have likely kept the portfolio alive past 100.
The lesson: the average return is not the return that kills you. The order is. A stress test that shows you "what if the bad draw happens in year one" is the single most useful planning exercise most retirees never run.
If you spend 20 minutes on r/retirement, r/personalfinance, or r/FIRE, the same themes repeat. Here is what the community tends to converge on about stress-testing, paraphrased for the FigureNerd voice.
Q: "The 4 percent rule says I'm fine. Why are so many people in this sub worried?"
Community consensus: the 4 percent rule is a historical backtest with a 30-year window. FIRE retirees often have 40 to 50 year windows. Morningstar and Wade Pfau research lands closer to 3.3 to 3.5 percent for today's valuations and a longer horizon. The real takeaway from the sub is: the 4 percent number is the single worst-case historical outcome, but for a 50-year window at current valuations, that floor drops. Plan conservatively, then let real returns surprise you up, not down.
Q: "Should I buy long-term-care insurance or self-insure?"
Community consensus: it depends on net worth. Under ~$500K in assets, LTC insurance is often worth the premium because a single long-term-care event can wipe out the entire nest egg. Over ~$2M in assets, self-insuring from the portfolio is usually the math answer because the premium cost over 20 years often exceeds the claim value. In the middle ($500K to $2M), hybrid life-plus-LTC policies and CCRC (continuing-care retirement community) entrance fees come up as alternatives. The single biggest mistake people report: waiting until 70+ to buy LTC, when premiums triple or denials become common.
Q: "My advisor ran one projection and said I'm fine. How do I stress test on my own?"
Community consensus: the single most useful free move is to run portfoliovisualizer.com's Monte Carlo Simulation or Empower's retirement planner with pessimistic return assumptions (4 to 5 percent instead of 7). If the plan survives at 5 percent with a bear-market-in-year-1 toggle, you have margin. Also widely shared: the "bucket strategy" (2 to 3 years of spending in cash, 5 to 7 years in bonds, the rest in equities) as a structural defense against sequence-of-returns risk. Nobody should accept "you're fine" from a single optimistic projection.
The Longevity Turd only wins when you run one scenario and call it done. Five minutes with the calculator above, honest inputs, one or two levers pulled if something comes back yellow or red. That is the difference between hoping for a good draw and actually planning for a range of them.
There is a point where a generic calculator, even a good one, is not enough. If any of these describes you, a fee-only Certified Financial Planner (typically $2,500 to $7,500 for a full plan, or 0.5 to 1 percent of assets as an ongoing fee) pays for itself many times over.
For straightforward "will my savings last" questions with one state, no pension, and a typical Social Security benefit, the calculator above is usually within a few years of what a CFP's projection would be. Use it as the first pass, then pay for a CFP when the stakes cross the seven-figure line.
Honest answer: no one knows the market or your lifespan with certainty. Retirement planners size the runway to age 95 or 100 as a safety buffer, because roughly one in four 65-year-olds today will reach 90 and one in ten will reach 95. A single base-case projection is not enough. The way to answer the question responsibly is to run multiple scenarios: base case, bear market sequence of returns, long life to 100, surprise medical event, forced early retirement. If your plan survives all five, you have a durable plan. If it fails in two or more, you have levers to pull.
A retirement stress test runs your plan against adverse scenarios instead of a single optimistic projection. Common stresses include a bear market in the first five years of retirement (sequence-of-returns risk), a longer life than actuarial average (to age 95 or 100), a large surprise medical expense at age 75 ($50,000 to $100,000 is typical), and a forced early retirement from job loss at age 60 to 62. If the plan survives each stress individually and a combined worst case, it's durable. If it fails in two or more, adjust before you stop working, not after.
Sequence-of-returns risk is the danger that the order of investment returns, not just the average, can ruin a retirement plan. Two retirees with the exact same 7 percent average return across 30 years can end up with wildly different outcomes if one hit a bear market in year one versus year twenty. Early-retirement losses are devastating because the retiree is withdrawing from a shrinking balance, which the subsequent recovery cannot fully repair. A 2008-style 25 to 35 percent drawdown in the first five years of retirement can shave a decade off the runway even if the long-term average return stays the same.
It depends on spending, return, inflation, and guaranteed income. At $70,000 per year spending, 6 percent return, 3 percent inflation, with a $2,400 monthly Social Security check, $1,000,000 typically lasts 28 to 35 years in the base case, which is a comfortable runway for a retirement starting at 65. Under a bear-market stress (a 25 percent drop in the first five years), the same nest egg often lasts only 20 to 24 years. Under a long-life scenario with no bear market, it lasts into the early 90s. The honest answer is: it depends which scenario shows up.
The classic 4 percent rule, based on William Bengen's 1994 research, says a retiree can withdraw 4 percent of the starting balance in year one and inflation-adjust the dollar amount afterward for 30 years. Modern research from Morningstar and Wade Pfau, reflecting today's higher stock valuations and lower projected bond returns, has landed closer to 3.3 to 4.0 percent as a defensible starting range. For a conservative plan, 3.5 percent is a reasonable default. For a plan that includes dynamic withdrawal (Guyton-Klinger guardrails), 4.5 to 5.0 percent can be sustainable with the discipline to cut spending in down markets.
As of 2026, ten states still tax at least some Social Security benefits: Colorado, Connecticut, Kansas, Minnesota, Montana, New Mexico, Rhode Island, Utah, Vermont, and West Virginia. West Virginia is in the final phase-out. Most states offer income-based exemptions that shield lower-income retirees entirely. Higher-income retirees in these states typically see 3 to 10 percent of their benefit taxed away. The other 40 states and DC exempt Social Security from state tax entirely.
Disclaimer. This calculator is for educational purposes only and does not constitute financial, investment, tax, or retirement planning advice. Retirement outcomes depend on market performance, life expectancy, tax laws, and individual circumstances. Consult a qualified Certified Financial Planner, fiduciary advisor, or CPA for advice specific to your situation.