Coast FIRE is the moment when your invested assets are large enough that compound growth alone — with zero additional contributions — will carry you to full financial independence by traditional retirement age. It is a profound milestone that permanently changes how you think about work.
Written by Mike Starr
Founder, StackedTomorrow · M.S. Organizational Management
Last Reviewed: August 2026
Educational Content Only. All content on this page is provided for informational and educational purposes only. It does not constitute financial, investment, legal, tax, or retirement advice. The calculators and projections shown are illustrative models — not predictions or guarantees of future performance. Past performance does not guarantee future results. Always consult a qualified financial professional before making investment or retirement decisions.
To understand Coast FIRE, you first need to understand the broader FIRE framework. The full FIRE goal is accumulating a portfolio large enough that a 4% annual withdrawal covers all living expenses indefinitely. But Coast FIRE is an intermediate milestone — a point years before full FIRE where you can stop investing and still reach that destination.
The word "coast" is the key. Once a ship has enough momentum, you can cut the engine and coast to the destination. Coast FIRE is that momentum point — the portfolio size at which compound interest alone will do the rest of the work.
Coast FIRE Number = Full FIRE Target ÷ (1 + r)^n
r = assumed annual real return · n = years until target retirement age
After hitting this number, you no longer need to invest for retirement. You simply need to earn enough to cover your current living expenses — which is a dramatically lower bar than saving aggressively for the future simultaneously.
Meet Maya, 32. Her full FIRE target is $1,500,000 (she spends $60,000/year; $60,000 × 25 = $1,500,000). She plans to fully retire at 65. Using a 7% real annual return assumption:
Maya's Coast FIRE Calculation:
Full FIRE target: $1,500,000
Years to retirement (65 − 32 = 33 years)
Assumed real return: 7%
Coast FIRE = $1,500,000 ÷ (1.07)^33 = ≈ $165,000
Once Maya has $165,000 invested, she can stop contributing entirely and — assuming 7% average annual growth — reach $1,500,000 by age 65.
Maya is currently investing aggressively and projects she will hit $165,000 by age 34 — just two more years of concentrated saving. After that, she can take a part-time job she loves, travel more, or shift to a lower-paying career she finds more meaningful. Her retirement is mathematically secured.
Source: Coast FIRE calculations use historical real returns as a planning assumption. Actual future returns may differ significantly. Conservative investors should model with 5–6% real return rather than 7%.
The following table shows how much you need invested today to reach a $1,500,000 full FIRE target by age 65, depending on your current age — assuming 7% real annual return:
| Your Age Now | Years to Coast | Coast FIRE Number (for $1.5M target) |
|---|---|---|
| 25 | 40 | ~$99,000 |
| 30 | 35 | ~$141,000 |
| 35 | 30 | ~$197,000 |
| 40 | 25 | ~$277,000 |
| 45 | 20 | ~$388,000 |
| 50 | 15 | ~$543,000 |
These are approximations. Use our FIRE Calculator for exact projections based on your target.
The FIRE community consistently reports that hitting Coast FIRE — even before reaching full financial independence — produces a profound shift in perspective. Specifically:
You no longer need a high-income job to fund your future. A modest income that covers current expenses is sufficient. This dramatically expands career choices.
The existential fear of "I'll never be able to retire" is eliminated mathematically. Market downturns are less threatening because you are not in active accumulation mode — you just need time, which you have.
Many people accept worse jobs for higher pay when they need every dollar for retirement savings. After Coast FIRE, you can optimize for meaning, autonomy, or work-life balance instead of purely for salary.
Portfolio will grow to full FIRE target without additional contributions. Work only to cover current expenses. Stop investing. Full retirement still decades away, but secured.
Portfolio covers most expenses when combined with part-time income. May still be contributing, but significantly less. Often coupled with employer health insurance from a part-time job. See our Barista FIRE guide.
Portfolio is large enough to sustain 100% of expenses via the 4% rule indefinitely. Work is fully optional. No income required.
Use the FIRE calculator to find both your full FIRE target and your Coast FIRE milestone.
Open the FIRE Calculator