| Age | Portfolio Value | Coast FIRE # | FI Progress | Gap / Surplus | Coast Reached? |
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Coast FIRE (Coast Financial Independence, Retire Early) is a milestone on the path to full financial independence. Once you reach your Coast FIRE number, you have enough invested that — even without adding a single additional dollar — your portfolio will grow to support your retirement lifestyle at your target retirement age.
In other words, you can "coast" the rest of the way. You still need income to cover living expenses, but you're no longer required to save aggressively for retirement.
Where r is your expected annual return rate and t is the number of years until retirement. The idea: today's Coast FIRE number compounded at rate r for t years equals your FI Number.
Inflation: Use a real (inflation-adjusted) return rate so your spending figure stays in today's dollars. If your expected nominal return is 10% and inflation is 3%, use 7%.
Taxes: This calculator does not account for taxes. In tax-advantaged accounts (Roth IRA, etc.) growth may be tax-free; in taxable accounts, capital gains taxes apply. Adjust your target accordingly.
Sequence of returns risk: Real markets are volatile. A higher Coast FIRE number (lower SWR) provides a larger safety margin against bad market timing early in retirement.
This is not financial advice. Use this as an educational tool and consult a qualified financial planner for personalized guidance.
Enter your current age, target retirement age, annual expenses in retirement, current portfolio value, and expected annual return. The calculator finds your full FIRE number (25× annual expenses), then works backwards to show your Coast FIRE number — the amount you need invested today so that compound growth alone reaches your FIRE number by retirement, with zero additional contributions. It also shows how many years (if any) remain until you hit your Coast number.
Coast FIRE is the point where your invested portfolio is large enough that — even if you never invest another dollar — compound growth will carry it to your full FIRE number by your target retirement age. The term "coasting" refers to letting your investments do the work while you ease off aggressive saving. Once you reach your Coast number, you only need to earn enough to cover your current living expenses. You can shift to a lower-stress job, work part-time, or pursue passion projects without worrying about retirement savings.
Coast FIRE Number = FIRE Number ÷ (1 + r)^n, where FIRE Number = annual expenses × 25, r = expected annual real return, and n = years until retirement. For example: if your annual expenses are $50,000, your FIRE number is $1,250,000. With 28 years to retirement at 7% returns: Coast Number = $1,250,000 ÷ (1.07)^28 = approximately $197,000. Save $197,000 by 37 and you can stop all retirement contributions — and still retire at 65 with $1,250,000.
Coast FIRE: investments are on track for retirement, but you still need earned income to cover current expenses — just no longer need to save for retirement. Barista FIRE (named after part-time café work): semi-retired with light part-time work to cover basic costs, investments growing but perhaps not yet at the full Coast number. Full FIRE: total financial independence — portfolio generates enough to cover all living expenses, no work required. Coast FIRE typically arrives 10–15 years before full FIRE, making it a meaningful and motivating intermediate milestone.
For long-term projections, most FIRE community planners use 7% real (inflation-adjusted) returns, based on historical US stock market performance (~10% nominal minus ~3% inflation). Conservative planners use 5–6%. The real rate matters because your expenses in retirement are stated in today's dollars — using real returns keeps the math consistent. A lower assumed return gives you a higher, safer Coast number with more margin for error.
Coast FIRE is powerful because of asymmetry: saving aggressively early has a disproportionate long-term payoff due to compound interest. Someone who invests heavily in their 20s and hits their Coast number at 30 can then work a low-stress job for 20 years and still retire comfortably — while someone who started at 40 must continue intense saving until traditional retirement age. Coast FIRE decouples financial security from career trajectory, which reduces anxiety, enables career pivots, and often leads to better life satisfaction even before full FI.