Coast FIRE Calculator

At a 7% real return, money invested at age 35 multiplies roughly 7.6 times by 65 (1.07 compounded for 30 years). So $150,000 at 35 grows to about $1,141,838 with no further contributions, and $200,000 grows to about $1,522,451 — enough to support roughly $61,000 a year of retirement spending at a 4% withdrawal rate ($1,522,451 × 4% ≈ $60,898). To find your own threshold, take whatever portfolio you want at 65 and divide by 7.6: that quotient is the balance that lets a 35-year-old stop contributing today and still arrive on time.

A $200,000 balance at age 40 grows to about $1,085,487 by 65 at a 7% real return ($200,000 × 1.07^25) with zero new contributions. At a 4% withdrawal rate, that funds roughly $43,000 a year of retirement spending ($1,085,487 × 4% ≈ $43,419). If your planned retirement budget is near that figure, a 40-year-old with $200,000 has effectively reached coast FIRE. If you plan to spend more, keep contributing until today's balance times 5.43 (the value of 1.07^25) covers 25 times your target annual spending.

Compounding makes identical dollars dramatically more valuable the earlier they are invested. $100,000 invested at age 30 grows to about $1,067,658 by 65 at a 7% real return, while the same $100,000 first invested at 35 reaches only about $761,226 — a gap of roughly $306,000 from a five-year head start, with no extra money saved. This is why coast FIRE rewards front-loading: aggressive saving in your late twenties and early thirties buys decades of growth, after which career downshifts, sabbaticals, or lower-paying meaningful work no longer threaten the retirement date.

Yes, but the bar is higher because only 20 compounding years remain. Money invested at 45 multiplies about 3.87 times by 65 at a 7% real return (1.07^20), so $250,000 grows to roughly $967,421 and $300,000 to roughly $1,160,905. At a 4% withdrawal rate those portfolios support about $38,700 and $46,400 a year respectively. A 45-year-old with $300,000 saved and a $45,000 retirement budget is close enough to coast; one targeting $80,000 a year still needs continued contributions, a later retirement age, or both.