Lean FIRE / Fat FIRE Calculator
Compare Lean FIRE, Standard FIRE and Fat FIRE.
See how different spending levels affect your FIRE target and the age at which you could reach financial independence.
Your Inputs
FIRE Spending per Month
Your Results
Share scenario
Copy a link with your current inputs.
Progress Toward Standard FIRE
Your portfolio currently covers about 2.8 years years of your annual target expenses.
Note: Lean FIRE and Fat FIRE mainly differ in their monthly spending assumptions. This calculator is a simplified projection and does not account for taxes, fees, or market volatility.
Portfolio Growth
This chart shows your projected portfolio growth together with your Lean FIRE, Standard FIRE and Fat FIRE targets.
Annual Projection
The table shows your simulated portfolio growth year by year and how large the remaining gap is to Lean FIRE, Standard FIRE and Fat FIRE.
Tip: You can scroll the table sideways.
| Year | Age | Portfolio | Lean FIRE Gap | Standard FIRE Gap | Fat FIRE Gap |
|---|---|---|---|---|---|
| 0 | 35 | 100.000 € | 350.000 € | 800.000 € | 1.700.000 € |
| 1 | 36 | 117.000 € | 333.000 € | 783.000 € | 1.683.000 € |
| 2 | 37 | 134.850 € | 315.150 € | 765.150 € | 1.665.150 € |
| 3 | 38 | 153.593 € | 296.408 € | 746.408 € | 1.646.408 € |
| 4 | 39 | 173.272 € | 276.728 € | 726.728 € | 1.626.728 € |
| 5 | 40 | 193.936 € | 256.064 € | 706.064 € | 1.606.064 € |
| 6 | 41 | 215.633 € | 234.367 € | 684.367 € | 1.584.367 € |
| 7 | 42 | 238.414 € | 211.586 € | 661.586 € | 1.561.586 € |
| 8 | 43 | 262.335 € | 187.665 € | 637.665 € | 1.537.665 € |
| 9 | 44 | 287.452 € | 162.548 € | 612.548 € | 1.512.548 € |
| 10 | 45 | 313.824 € | 136.176 € | 586.176 € | 1.486.176 € |
| 11 | 46 | 341.515 € | 108.485 € | 558.485 € | 1.458.485 € |
| 12 | 47 | 370.591 € | 79.409 € | 529.409 € | 1.429.409 € |
| 13 | 48 | 401.121 € | 48.879 € | 498.879 € | 1.398.879 € |
| 14 | 49 | 433.177 € | 16.823 € | 466.823 € | 1.366.823 € |
| 15 | 50 | 466.836 € | reached | 433.164 € | 1.333.164 € |
| 16 | 51 | 502.177 € | reached | 397.823 € | 1.297.823 € |
| 17 | 52 | 539.286 € | reached | 360.714 € | 1.260.714 € |
| 18 | 53 | 578.251 € | reached | 321.749 € | 1.221.749 € |
| 19 | 54 | 619.163 € | reached | 280.837 € | 1.180.837 € |
| 20 | 55 | 662.121 € | reached | 237.879 € | 1.137.879 € |
| 21 | 56 | 707.227 € | reached | 192.773 € | 1.092.773 € |
| 22 | 57 | 754.589 € | reached | 145.411 € | 1.045.411 € |
| 23 | 58 | 804.318 € | reached | 95.682 € | 995.682 € |
| 24 | 59 | 856.534 € | reached | 43.466 € | 943.466 € |
| 25 | 60 | 911.361 € | reached | reached | 888.639 € |
| 26 | 61 | 968.929 € | reached | reached | 831.071 € |
| 27 | 62 | 1.029.375 € | reached | reached | 770.625 € |
| 28 | 63 | 1.092.844 € | reached | reached | 707.156 € |
| 29 | 64 | 1.159.486 € | reached | reached | 640.514 € |
| 30 | 65 | 1.229.460 € | reached | reached | 570.540 € |
| 31 | 66 | 1.302.933 € | reached | reached | 497.067 € |
| 32 | 67 | 1.380.080 € | reached | reached | 419.920 € |
| 33 | 68 | 1.461.084 € | reached | reached | 338.916 € |
| 34 | 69 | 1.546.138 € | reached | reached | 253.862 € |
| 35 | 70 | 1.635.445 € | reached | reached | 164.555 € |
| 36 | 71 | 1.729.217 € | reached | reached | 70.783 € |
| 37 | 72 | 1.827.678 € | reached | reached | reached |
| 38 | 73 | 1.931.062 € | reached | reached | reached |
| 39 | 74 | 2.039.615 € | reached | reached | reached |
| 40 | 75 | 2.153.596 € | reached | reached | reached |
| 41 | 76 | 2.273.276 € | reached | reached | reached |
| 42 | 77 | 2.398.940 € | reached | reached | reached |
| 43 | 78 | 2.530.887 € | reached | reached | reached |
| 44 | 79 | 2.669.431 € | reached | reached | reached |
| 45 | 80 | 2.814.903 € | reached | reached | reached |
| 46 | 81 | 2.967.648 € | reached | reached | reached |
| 47 | 82 | 3.128.030 € | reached | reached | reached |
| 48 | 83 | 3.296.432 € | reached | reached | reached |
| 49 | 84 | 3.473.253 € | reached | reached | reached |
| 50 | 85 | 3.658.916 € | reached | reached | reached |
| 51 | 86 | 3.853.862 € | reached | reached | reached |
| 52 | 87 | 4.058.555 € | reached | reached | reached |
| 53 | 88 | 4.273.483 € | reached | reached | reached |
| 54 | 89 | 4.499.157 € | reached | reached | reached |
| 55 | 90 | 4.736.115 € | reached | reached | reached |
What is Lean FIRE?
Lean FIRE describes financial independence with comparatively low monthly expenses. The goal is to reach financial independence as early as possible by keeping your lifestyle lean and your FIRE target relatively low.
Someone pursuing Lean FIRE needs less wealth than with Standard FIRE or Fat FIRE. The tradeoff is that the financial margin is usually smaller, so unexpected expenses can matter much more.
What is Fat FIRE?
Fat FIRE describes financial independence with high monthly expenses and a more comfortable lifestyle. The goal is not only independence, but also a larger safety margin and more lifestyle flexibility.
Fat FIRE requires significantly more wealth. In return, it can better reflect higher spending for travel, housing, family, healthcare, hobbies or a larger long-term safety buffer.
Frequently Asked Questions About Lean FIRE and Fat FIRE
What is the difference between Lean FIRE and Fat FIRE?
Lean FIRE is based on low monthly expenses and a relatively frugal lifestyle. Fat FIRE is based on higher expenses and a more comfortable lifestyle.
Is Lean FIRE more risky?
Lean FIRE can be riskier because there is less room for unexpected expenses, inflation, healthcare costs or major life changes.
Why does Fat FIRE require so much more wealth?
Your FIRE number is directly based on your annual expenses. If your monthly spending is twice as high, your required FIRE portfolio is roughly twice as high as well.
Is this calculator financial advice?
No. This calculator is for educational and informational purposes only and does not replace personal financial advice, tax advice or retirement planning.
Explore Other FIRE Calculators
Lean FIRE and Fat FIRE show different spending levels. If you want to calculate classic FIRE, part-time FIRE or whether your current portfolio can coast to your goal, try the other FIRE calculators.