Coast FIRE: The Number That Lets You Stop Saving for Retirement

Traditional FIRE is a single destination: the point where your portfolio can fund all expenses indefinitely at a safe withdrawal rate, with no additional income required. Coast FIRE is an earlier waypoint: the point where your portfolio, left entirely alone with no new contributions, will compound to your full FIRE number by traditional retirement age.

Someone who reaches Coast FIRE at 32 still works. Their paycheck covers current living expenses. But they no longer need to save a single dollar for retirement — the existing portfolio is on track to reach the target through compound growth alone. This changes the relationship with work fundamentally: any job that covers expenses is sufficient, regardless of how it compares to peak earning years.

The term 'coasting' describes the state after reaching this threshold. You have climbed the hill — the compounding does the rest. You can coast downhill, choosing work based on preference and lifestyle rather than retirement savings requirements.

Coast FIRE Number = FIRE Number ÷ (1 + r)^n. The FIRE number is your target retirement portfolio — annual expenses times 25 at a 4% withdrawal rate. r is your expected annual real return (after inflation; commonly 5–7%). n is the number of years until traditional retirement — usually the target age minus your current age.

At 7% real return with a $1,000,000 FIRE number: a 30-year-old needs approximately $131,000 to have coasted to FIRE by 65. A 35-year-old needs approximately $184,000. A 40-year-old needs approximately $258,000. Every five-year delay in reaching Coast FIRE roughly doubles the required investment, because you have removed 5 years of compound growth from the calculation.

These numbers assume no additional contributions after hitting Coast FIRE. In practice, most people continue earning and saving after reaching it — which means their actual FIRE date advances significantly beyond traditional retirement age. Coast FIRE is a waypoint that transforms the pressure on ongoing savings without requiring full retirement.

The most profound effect of Coast FIRE is the career optionality it creates. Before Coast FIRE, career decisions are constrained by the need to maximize retirement contributions. After Coast FIRE, any job covering current expenses is financially viable — you can choose based on meaning, flexibility, location, or lifestyle rather than compensation alone.

This often means accepting a lower-paying but more satisfying job: teaching, creative work, nonprofit roles, or reduced hours. The financial pressure to maximize income disappears because income only needs to match current spending, not current spending plus retirement savings.

For many people on a traditional FIRE path, reaching Coast FIRE 10–15 years before full FIRE is a natural plateau — a point where the most restrictive financial pressure is released while continuing to compound toward full financial independence.

Coast FIRE focuses on investment accumulation: you have enough invested that compounding covers traditional retirement, and current income only needs to fund current expenses. Barista FIRE focuses on income reduction: you have invested enough that part-time or lower-stress work (like the barista analogy) produces enough income for current expenses without full retirement savings.

The practical difference is timing and certainty. Coast FIRE has a precise mathematical threshold — you either have the calculated number or you do not. Barista FIRE depends on whether part-time income actually covers expenses, which varies by location and lifestyle.

Full FIRE eliminates the income requirement entirely — investments fund everything. Coast and Barista FIRE are intermediate states that provide meaningful freedom earlier, at the cost of still requiring some income. Which target makes sense depends on your relationship with work, your current savings rate, and how urgently you want to reduce income pressure.