FIRE Calculator

What is FIRE?

FIRE stands for Financial Independence, Retire Early. The idea: once your investments are large enough that a safe withdrawal each year covers your expenses, work becomes optional. The most common benchmark is the 4% rule — you can withdraw about 4% of your portfolio per year, which means you need roughly 25× your annual expenses invested.

How this is calculated

FIRE number = annual expenses ÷ withdrawal rate (4% → ×25). To estimate years to FI, we grow your current investments each year by your expected real return and add your annual savings, until the balance reaches your FIRE number. Returns are assumed "real" (after inflation), so today's dollars stay comparable. Markets vary, so treat this as a planning estimate, not a promise.

Educational estimate, not investment advice — see our disclaimer.

Types of FIRE

FIRE stands for Financial Independence, Retire Early, but it means different things to different people. A few common flavors:

• Lean FIRE — reaching independence on a modest, frugal budget, often with lower annual spending.
• Fat FIRE — building a larger nest egg to support a comfortable, higher-spending lifestyle.
• Coast FIRE — saving enough early that compounding alone can carry you to retirement without new contributions.
• Barista FIRE — partly retiring while keeping a part-time job, often for income or benefits like health coverage.

A FIRE number example

A widely used starting point is to multiply your expected annual expenses by about 25. Say you expect to spend $40,000 per year in retirement. Using the 25x guideline, your rough FIRE number would be $1,000,000. If your spending were closer to $50,000, that target would rise to about $1,250,000.

How fast you reach a number like this depends heavily on your savings rate. Someone saving 20% of their income typically takes much longer than someone saving 50%, because a higher savings rate both grows the nest egg faster and lowers the spending the nest egg has to cover. You can explore how contributions grow over time with our compound interest calculator.

The 4% rule and its caveats

The 4% rule is a popular guideline suggesting you might withdraw about 4% of your portfolio in the first year of retirement, then adjust for inflation each year after. It is the origin of the 25x shortcut (1 divided by 0.04 equals 25). It is a rule of thumb, not a guarantee.

One important caveat is sequence-of-returns risk: poor market performance in the early retirement years can do more lasting damage than the same poor returns later, because withdrawals shrink a portfolio that has not had time to recover. Partly for this reason, some people prefer a more conservative withdrawal rate, such as 3.5%, which raises the target nest egg but can add a margin of safety. These are general illustrations, not personalized recommendations.

Why your savings rate matters most

While investment returns get a lot of attention, your savings rate often has the largest effect on how soon you reach financial independence. A higher savings rate accelerates the timeline from both directions at once: more money flows in each year, and the lifestyle you need to fund is smaller.

Because of this, modest, consistent increases in how much you save can shift your target date more than chasing slightly higher returns. Setting a clear monthly target can help — our savings goal calculator can show what it takes to hit a specific number by a chosen date.

Common mistakes to avoid

• Underestimating expenses — forgetting irregular costs like home repairs, travel, or replacing a car.
• Ignoring healthcare — coverage before traditional retirement age can be a significant and easily overlooked expense.
• Assuming high returns — planning around optimistic growth rates can leave little room when markets underperform.
• No margin of safety — building a plan with zero cushion makes it fragile to surprises and bad timing.