FIRE Calculator - Financial Independence, Retire Early

To use this FIRE calculator, start by entering your current age and your target retirement age, which is the age at which you hope to achieve financial independence. Next, enter your current savings, including all investment accounts, brokerage balances, and retirement funds such as 401(k) and IRA balances that you plan to use during early retirement.

Enter your annual income (gross, before taxes) and your savings rate as a percentage. Your savings rate is the portion of your after-tax income that goes directly into investments each year. Most FIRE aspirants target a savings rate between 25% and 70%. Set the expected annual return to reflect your anticipated average investment growth after inflation. A common assumption for a diversified stock portfolio is 7%, though more conservative planners use 5% to 6%.

Finally, enter your annual expenses. This is the most critical input because it determines your FIRE number. Be thorough when estimating expenses: include housing, food, transportation, insurance, utilities, entertainment, travel, and any recurring costs. It is especially important to account for healthcare costs, which can be substantial before you qualify for Medicare at age 65. Many early retirees budget $500 to $1,500 per month for health insurance premiums purchased on the open market.

Once all inputs are entered, the calculator instantly displays your FIRE number, projected savings at your target retirement age, estimated years to FIRE, and the monthly savings needed to stay on track. Experiment by adjusting your savings rate or expenses to see how small changes can dramatically shorten or lengthen your timeline.

A FIRE calculator is a planning tool designed for followers of the Financial Independence, Retire Early movement. FIRE is a lifestyle strategy centered on aggressive saving, disciplined investing, and intentional spending so that you can accumulate enough wealth to cover your living expenses indefinitely, freeing you from the need to work for a paycheck decades before the traditional retirement age of 65.

The FIRE movement gained mainstream attention through influential voices like Mr. Money Mustache, whose blog demonstrated that a middle-class family could retire in their thirties by maintaining a high savings rate, and Jacob Lund Fisker, author of Early Retirement Extreme, who showed how to live well on a fraction of a typical salary. Since then, the movement has grown into a diverse community with several distinct approaches.

Lean FIRE targets financial independence on a minimalist budget, typically under $40,000 per year in living expenses, requiring a smaller portfolio. Fat FIRE aims for a more comfortable or even luxurious retirement with annual spending above $100,000. Barista FIRE is a hybrid approach where you accumulate enough investments to cover most of your expenses but continue working part-time for supplemental income and benefits like health insurance. Coast FIRE means you have already saved enough that compound growth alone will fund a traditional retirement, so you only need to earn enough to pay current bills.

At the heart of every FIRE plan is the 4% rule, derived from the 1998 Trinity Study, which found that a retiree withdrawing 4% of a diversified stock-and-bond portfolio in the first year of retirement and adjusting for inflation each subsequent year had a very high probability of not running out of money over a 30-year period. This rule translates directly into your FIRE number: multiply your expected annual expenses by 25. FIRE has gained popularity because it offers a clear, mathematically grounded roadmap to freedom, giving people a concrete target to work toward rather than a vague hope of someday retiring.

The core FIRE formula is straightforward:

FIRE Number = Annual Expenses × 25

This multiplier of 25 comes directly from the 4% safe withdrawal rate. If you withdraw 4% of your portfolio each year, you need a portfolio that is 1 / 0.04 = 25 times your annual spending. For example, if you spend $40,000 per year, your FIRE number is $1,000,000. If you prefer a more conservative 3.5% withdrawal rate, the multiplier becomes approximately 28.6.

Your savings rate has a powerful effect on the time it takes to reach FIRE. At a 10% savings rate, it takes roughly 51 years. At 25%, about 32 years. At 50%, approximately 17 years. At 75%, only about 7 years. This is because a higher savings rate simultaneously increases how much you invest and decreases the amount your portfolio must sustain.

Portfolio growth over time is projected using the future value formula with regular contributions:

FV = PV × (1 + r)n + PMT × [((1 + r)n − 1) / r]

The calculator uses this formula to project your portfolio balance at each point in time and determines the crossover point where your savings meet or exceed your FIRE number.

Example 1 – Lean FIRE ($40,000/year expenses): Maria is 28 years old, earns $70,000 per year, and has $30,000 in savings. She lives frugally and spends $40,000 annually. Her FIRE number is $40,000 × 25 = $1,000,000. She maintains a 35% savings rate, saving approximately $24,500 per year ($2,042 per month). Assuming a 7% annual return, Maria is projected to reach her FIRE number in about 18 years, allowing her to achieve financial independence around age 46. By cutting expenses further or increasing her income, she could shorten this timeline significantly.

Example 2 – Regular FIRE ($60,000/year expenses): James is 32, earns $110,000 per year, and has $80,000 in current savings. He expects to spend $60,000 per year in retirement, giving him a FIRE number of $60,000 × 25 = $1,500,000. With a 45% savings rate, James saves $49,500 per year ($4,125 per month). At a 7% expected return, his portfolio is projected to cross $1,500,000 in roughly 14 years, putting him on track for financial independence at age 46. His existing $80,000 head start gives him a meaningful advantage thanks to compound growth.

Example 3 – Fat FIRE ($100,000/year expenses): Sarah and David are a dual-income couple, both age 35, earning a combined $250,000. They have $200,000 in savings and want to maintain a comfortable $100,000 annual lifestyle in retirement. Their FIRE number is $100,000 × 25 = $2,500,000. Together they save 50% of their income, or $125,000 per year ($10,417 per month). With a 7% return, they are projected to reach their FIRE number in approximately 11 years, achieving financial independence around age 46. Their higher income and aggressive savings rate offset the much larger target portfolio required for Fat FIRE.