FatFIRE Math

Work-versus-retire calculator

What does one more year buy?

Compare retiring now with working for up to five more years. The calculation includes new contributions, historical returns during those years and a shorter retirement.

Your plan

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Allocation
Stocks with a fifth in 10-year Treasuries — the usual Fat FIRE accumulation mix.
3 more years buys$23,700/yrAdditional annual retirement spending that survived every historical start.
Retire now supports$107,580/yrStrict historical floor over 40 retirement years.
Retire in 3 years supports$131,280/yrMore saving, more growth, and fewer years to fund.
Portfolio added by work alone$300,000Contributions only; market growth is additional.

Working 3 more years raised the annual spending that survived every historical sequence by $23,700 — from $107,580 to $131,280 a year.

Exhibit 1 — where the delayed plan endedOne bar per historical start
Ending portfolio by historical starting year$0$10M$20M$30M193019401950196019701980
The plan works 3 more years, adds $100,000 at the start of each year, then funds 40 years of retirement. Rust marks a depleted portfolio.
Exhibit 2 — what each additional year boughtStrict historical floor
Historically sustainable spending by years worked$0$50k$100k$150kNow+1y+2y+3y+4y+5y
Each point is the highest annual spending that survived every complete historical sequence after working that many additional years.
Historical startLowest pointEnded withResult
Worst endingStarted in 1966$1,309,613$1,652,268Held
Median endingStarted in 1946$2,459,280$16,812,861Held
Best endingStarted in 1982$3,000,000$67,080,110Held

Results use historical US returns. They are pre-tax, before fees and are not forecasts. Read why the last working years are worth so much, or see about and method.