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Will my savings last at this level of spending?
Enter your savings, spending and Social Security to see, across 10,000 simulated market futures, how likely your money is to last to 85, 90 and 95.
Yearfold is a financial-education tool. It is not a registered investment adviser and does not provide personalized investment, tax, or legal advice. Results are probabilistic projections based on historical data and stated assumptions; they are not guarantees. Methodology
By Mindaugas Laucius · Last reviewed October 21, 2026
Running 10,000 simulated futures…
How this works
A single average return hides the thing that breaks retirement plans: the order of returns. A crash in the first years of withdrawals does far more damage than the same crash a decade later. So instead of one projection, we replay 10,000 possible futures built from real monthly stock, bond and inflation history from 1928 to 2025, sampled together so high-inflation months keep their matching returns.
In every future you withdraw the same spending in today's dollars, adjusted for that path's inflation, and Social Security starts at the age you choose. We count how many futures still have money at 85, 90 and 95, and chart the median balance alongside a bad-luck path at the 10th percentile.
The "what spending gives 90% odds?" button searches for the monthly budget at which 9 of every 10 futures last to 95. It runs a quick 1,000-path search in your browser, then confirms the answer at full precision. Nothing you type leaves your device.
Worked example: Age 65, $800,000 saved, $5,000 a month of spending, $2,400 a month of Social Security from 67
- Before Social Security: $5,000 × 12 = $60,000 a year comes from savings, a 7.5% withdrawal rate on $800,000.
- From 67: Social Security covers $2,400, so savings supply $2,600 a month, or $31,200 a year.
- The early, larger withdrawals are when a bad market does the most harm, which is why the simulation looks at every sequence rather than an average.
The tool runs this exact case by default. Change any input and the odds recalculate; the full plan adds taxes, account types, a spouse and more.
The full method behind every Yearfold number is on the methodology page.
Sources
Rules verified against these sources on October 21, 2026.
Questions
Does the spending include taxes and health insurance?
Enter everything you expect to spend, including taxes and health premiums. This quick tool doesn't calculate taxes separately; the full calculator models federal tax, Medicare premiums and withdrawals by account type.
Is 100% the goal?
Not necessarily. Reaching 100% usually means spending far less than you could in most futures. Many planners treat roughly 80–90% as a reasonable target, paired with a willingness to trim spending if markets disappoint early.
Why do my odds change when I pick a different mix?
Conservative, balanced and growth mixes have different historical return and volatility patterns. More stocks usually raises the median outcome and widens the range, so the effect on the odds depends on how long the money must last.
What's included in the 10,000 futures?
Monthly returns and inflation are drawn together from 1928–2025 history, with a fixed seed so the same inputs always give the same answer. The full method, data sources and limits are on the methodology page.
See this in your full plan
The free 10,000-path calculator puts this answer next to everything else: savings, spending, Social Security, taxes, Medicare and a spouse, with the odds your money lasts. Your inputs from this tool carry over.
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