How Long Does FIRE Actually Take? Data From 155 Years of Markets

The MMM table is one number; reality is a distribution

The famous savings rate table gives you a single number: at a 50% savings rate, 17 years to FI. The number is computed assuming a smooth 5% real return, every year, forever.

Real markets don't deliver smooth 5% real returns every year. They deliver -15% then +25% then -8% then +18% then 0% — variable sequences that average to roughly 6.7% real over the very long run but vary wildly over any 15-20 year window. Two FIRE planners with identical savings rates and identical starting capital can have FIRE timelines that differ by 10+ years, purely based on which historical sequence they happened to live through.

The honest answer to "how long does FIRE take" isn't a number. It's a distribution.

The actual numbers

Running every starting cohort in the Shiller dataset from 1871 to 2014 (the latest year that allows a 10-year minimum projection), with a typical FIRE planner profile — £30,000 expenses, 75/25 allocation, real returns from each cohort's actual sequence:

For a 50% savings rate starting from zero:

• 10th percentile (worst sequences): 22 years
• 25th percentile: 19 years
• Median: 16.5 years
• 75th percentile: 14 years
• 90th percentile (best sequences): 12 years

The MMM table number (17 years) lands roughly between the median and 25th percentile. It's an honest middle estimate, but it misses both tails substantially.

The same calculation at a 30% savings rate:

• 10th percentile: 38 years
• Median: 28 years
• 90th percentile: 22 years

The percentile spread widens at lower savings rates because more years means more opportunity for sequence luck to compound. At 70% savings rate the spread compresses (10th–90th percentile gap is only 4–5 years) because the timeline is short enough that variance has less room to operate.

Why the spread exists

Sequence-of-returns risk doesn't just affect retirement — it affects accumulation too. Three mechanisms:

1. Early bull markets compress timelines. Someone starting in 1982 saw 16 years of 12%+ real returns in US equities. Their portfolio grew faster than the math implies; they hit FI earlier.
2. Early bear markets stretch timelines. Someone starting in 2000 saw a lost decade with roughly 0% real returns. The 5% assumption broke for 10 years; their timeline extended by years.
3. Late-stage volatility hits hardest. A 30% drop in year 15 (when the portfolio is large) costs more years to recover than a 30% drop in year 3.

The shape of the distribution: roughly symmetric around the median, but with fat tails on both ends. Truly catastrophic outcomes (40+ years to FI for a 50%-saver) are rare but possible. Truly fast outcomes (under 10 years for a 50%-saver) are equally rare.

How to use the distribution

Two practical implications:

1. Plan for the 25th percentile, not the median. Targeting the median means you'll be late 50% of the time. Targeting the 10th percentile means you'll over-save dramatically in most cohorts. The 25th percentile is a defensible balance.

2. Watch your cohort, not the average. Once you're 5+ years into your FIRE journey, you've already started to see which percentile your sequence is tracking. A bull market early in your accumulation puts you near the 75th percentile; you can probably accelerate plans. A bear market does the opposite.

This is fundamentally what historical sequence testing is for. The 5% smooth-return calculator gives you one number; the simulator gives you the distribution.

The conservative planning baseline

If you want a defensible number for your own planning:

• For 30% savings rate: plan for 30 years (the 25th percentile)
• For 40% savings rate: plan for 23 years
• For 50% savings rate: plan for 19 years
• For 60% savings rate: plan for 14 years
• For 70% savings rate: plan for 10 years

These are the years you should expect — with some chance of beating them comfortably and a smaller chance of being late.

The trick is to balance the math with behaviour. Saving 15% extra above what the median sequence requires is a small cost (about 1–2 years of additional accumulation) for a meaningful improvement in the chance of hitting FI by your target age.

Test your specific situation in our simulator — it shows the full distribution of FI dates for your savings rate, starting capital, and assumed allocation, against every historical cohort since 1871.