Coast FIRE Grid

Coast FIRE means you've saved enough money today that, even if you stop contributing new money, your existing investments will grow to support your retirement by your target retirement age.

Unlike traditional FIRE, which requires you to have your full FIRE Number saved, Coast FIRE lets you "coast"—you can work less, pursue lower-paying passions, or simply enjoy financial flexibility without worrying about retirement savings.

For example: If you need $1.25M for FIRE at 65, but you're 35 today, your Coast Number might only be $164,000. Once you hit that number, you can stop saving for retirement entirely—compound growth does the rest.

The Coast FIRE formula uses the time value of money concept, working backwards from your FIRE Number:

Where:

• FIRE Number = Annual Spending ÷ Safe Withdrawal Rate (typically 4%)
• Real Return = Investment Return - Inflation - Fees
• Years to Retirement = Target Retirement Age - Current Age

This grid uses real returns of 3.18% (conservative), 5.18% (baseline), and 7.18% (optimistic) after accounting for 3% inflation and 0.18% fees.

Choose the scenario that best matches your asset allocation and risk tolerance:

• Conservative (6%): If you're closer to retirement, prefer bond-heavy portfolios, or want to plan for lower returns. This provides a safety margin.
• Baseline (8%): If you have a balanced stock-bond portfolio (e.g., 60/40 or 70/30). This aligns with historical market returns.
• Optimistic (10%): If you're young, have a stock-heavy portfolio (80-100% equities), or want to see best-case scenarios. Be cautious—don't count on this!

Pro tip: Use the conservative scenario for planning purposes. If returns are better, you'll reach Coast FIRE even sooner. If they're worse, you're still prepared.

Age is the most powerful factor in Coast FIRE because of compound growth. The more years your money has to grow, the less you need to start with.

Example (Baseline scenario, $50k spending, retire at 65):

• Age 25: $164,000 Coast Number (40 years to compound)
• Age 35: $283,000 Coast Number (30 years to compound)
• Age 45: $489,000 Coast Number (20 years to compound)
• Age 55: $845,000 Coast Number (10 years to compound)

Notice the pattern: Each decade earlier you start, your Coast Number is roughly 40-50% lower. This is why financial experts emphasize starting early—even with small amounts.

Yes! Coast FIRE is perfect for people who have already started saving. Here's how to use this grid:

1. Find your current age in the grid and note the Coast Number for your situation.
2. Compare your current investments to that Coast Number.
3. If you've already reached it: Congratulations! You've achieved Coast FIRE. You can stop retirement contributions and redirect that money to other goals.
4. If you're close: Calculate the gap and ramp up savings temporarily to hit it.
5. If you're far from it: Use the gap as motivation. The grid shows you exactly what target to aim for.

Remember: Coast FIRE assumes you won't contribute more after reaching it. If you keep saving, you'll reach full FIRE even faster.

This grid shows common scenarios, but your situation might be different. Here's how to adapt:

• Different spending: Use our Coast FIRE Calculator for exact numbers. Or, estimate using the grid: Coast FIRE scales roughly linearly with spending (2x spending = 2x Coast Number).
• Different retirement age: Use View B to see the trend. Earlier retirement requires more; later retirement requires less. Interpolate between the ages shown.
• Already have savings: Subtract your current investments from the Coast Number to see your gap. If you're above it, you've achieved Coast FIRE!

For personalized calculations with your exact numbers, use our interactive Coast FIRE Calculator on the homepage.

Coast FIRE is ideal if you:

• Want financial flexibility but don't want to stop working entirely
• Have a long time horizon (15+ years until retirement)
• Can save aggressively now to "buy" future freedom
• Want the option to work part-time, switch careers, or start a business without worrying about retirement savings
• Value autonomy more than early retirement

Coast FIRE might NOT be ideal if you:

• Want to retire as early as possible (consider Lean FIRE instead)
• Are close to traditional retirement age (focus on full FIRE)
• Enjoy your career and want to maximize wealth (traditional saving/investing may be better)