What is my FIRE number?

Yearly spending divided by your withdrawal rate. At 4%, that is 25 times a year's spending: 1,000,000 for 40,000 a year. Use today's spending inflated to your FIRE date, which the page does for you.

Is the 4% rule safe for early retirement?

It was tested over 30-year periods. For a 40- or 50-year retirement, many planners suggest 3–3.5%, or a plan to cut spending after bad market years. Lower the withdrawal rate above to see the larger FIRE number it needs.

What are Lean FIRE, Fat FIRE and Coast FIRE?

Lean FIRE aims at a frugal budget and a smaller number; Fat FIRE at a comfortable one and a much larger number. Coast FIRE means saving enough early that growth alone reaches your number by normal retirement age, so you only need to cover current costs.

How do I reach FIRE faster?

The savings rate matters most: spending less both raises what you save and lowers the number you need. Going from saving 20% of income to 50% cuts the working years far more than an extra percentage point of return.

How is this different from the retirement calculator?

The retirement page works backwards from spending to the monthly saving you need. This one works forwards from your savings plan, in two phases, to the corpus you will have, and checks it against a FIRE number and a runway.

FIRE Calculator (Financial Independence, Retire Early)

Project your FIRE corpus from savings in two phases, compare it with your FIRE number at a safe withdrawal rate, and see how many years it lasts.

Inputs

CurrencyAuto (USD)

Current age

1860

FIRE target age

3070

Current savings

$0$1,030,900

Phase 1 monthly savings

$0$5,200

Monthly investment until phase 1 end age.

Phase 1 ends at age

2065

Phase 2 monthly savings

$0$5,200

Monthly investment from phase 1 end to FIRE age.

Expected return(%)

0 %20 %

Inflation(%)

0 %15 %

Current monthly spend

$52$5,200

Today's lifestyle cost — inflated to retirement for runway.

Safe withdrawal rate(%)

2 %6 %

Share of the corpus spent in the first year of retirement. 4% is the classic rule; lower is safer for retirements longer than 30 years.

Include CalculateEveryday mark

Corpus at retirement

$1,044,797

Retirement corpus

Starting savings$100,000 (10%)
From contributions and growth$944,797 (90%)

FIRE number at 4% withdrawal: $1,869,561
Short of the FIRE number by: $824,764
Monthly need at retirement: $6,232
Years of runway: 22 years
Years to FIRE: 15
Phase 1 monthly savings: $2,000
Phase 2 monthly savings: $3,000

Assumes 7% return during accumulation and withdrawal.
FIRE runway is illustrative — sequence-of-returns risk can shorten real-world sustainability.

Use this calculator on your own site

Free embed

Two lines of HTML, unlimited views
Shows a small CalculateEveryday bar, with a credit link under the calculator

What each FIRE input means

Current age: Your age today.
FIRE target age: The age you want to reach financial independence.
Current savings: Invested savings today, excluding your home and emergency fund.
Phase 1 monthly savings: What you invest each month in the first phase.
Phase 1 ends at age: The age the first phase ends — for example when a pay rise, a paid-off loan or a partner's income lets you save more.
Phase 2 monthly savings: What you invest each month from the end of phase 1 to your FIRE age.
Expected return: Average yearly return, before and after FIRE. Many FIRE plans assume 5–7% for a stock-heavy portfolio.
Inflation: Expected yearly price rise, applied to your spending until and during retirement.
Current monthly spend: What your life costs a month today, in today's money.
Safe withdrawal rate: Share of the corpus you plan to spend in the first year of retirement: 4% is the classic rule; 3–3.5% is common for retirements of 40–50 years.

FIRE formula

Each year: corpus = corpus × (1 + return) + 12 × monthly saving · FIRE number = yearly spending at FIRE age ÷ withdrawal rate · runway: years until withdrawals rising with inflation empty the corpus

FIRE — financial independence, retire early — means saving hard enough that investments can pay for your life, so work becomes optional decades before the usual retirement age. The core number is the FIRE number: your yearly spending divided by a safe withdrawal rate. At the classic 4%, from Bengen's 1994 study and the 1998 Trinity study of US market history, that is 25 times a year's spending; people retiring at 40 often use 3–3.5% because their money has to last 50 years, not 30. The page projects your savings to your FIRE age in two phases, since most people save more as income rises: the corpus grows at your expected return each year and that year's contributions are added. Today's spending is inflated to the FIRE date, the FIRE number is worked out at the withdrawal rate you choose, and the page shows whether the projected corpus is ahead or short. Finally it runs the corpus forward in retirement, withdrawing spending that rises with inflation while the rest keeps earning, and counts the years until it runs out — the runway.

FIRE worked example

A 30-year-old with $100,000 saved, investing $2,000 a month until 35 and $3,000 a month until 45 at 7%, builds a corpus near $1,044,797 by 45. Today's $4,000 a month inflates to about $6,232 by then, so the FIRE number at 4% is $1,869,561 — the plan is short by about $824,764. Spending that amount, rising with inflation each year, the corpus lasts about 22 years, to 67.

More FIRE examples

Starting with $50,000 and saving $3,500 a month in the second phase gives $989,744 at 45 — about 20 years of runway, and still about $879,817 short of the 4% FIRE number. Retiring later or spending less moves the result far more than a slightly higher return.

Where the FIRE calculator can give the wrong answer

Returns are assumed steady. A crash early in retirement, while withdrawals continue, can shorten the runway well below what a smooth average shows; that sequence risk is why early retirees often choose 3–3.5%.
The 4% rule was tested over 30-year retirements. FIRE retirements of 40–60 years need a lower rate, flexible spending, or other income.
Contributions are added once a year and the return applied annually, a simplification of monthly investing that slightly understates growth.
Taxes, health insurance before Medicare (or other public cover), and penalties for early withdrawal from retirement accounts are not modelled.
The runway stops counting at 80 years; a result of '80+' means withdrawals at that rate never empty the corpus under these assumptions.

Spotted a mistake? Tell us

FIRE reference table

FIRE number by yearly spending and withdrawal rate
Yearly spending	3.5% (× 28.6)	4% (× 25)	4.5% (× 22.2)
30,000	857,143	750,000	666,667
40,000	1,142,857	1,000,000	888,889
60,000	1,714,286	1,500,000	1,333,333
80,000	2,285,714	2,000,000	1,777,778

Source: FIRE number = yearly spending ÷ withdrawal rate (Bengen 1994; Trinity study 1998)

FIRE FAQ

: Yearly spending divided by your withdrawal rate. At 4%, that is 25 times a year's spending: 1,000,000 for 40,000 a year. Use today's spending inflated to your FIRE date, which the page does for you.
: It was tested over 30-year periods. For a 40- or 50-year retirement, many planners suggest 3–3.5%, or a plan to cut spending after bad market years. Lower the withdrawal rate above to see the larger FIRE number it needs.
: Lean FIRE aims at a frugal budget and a smaller number; Fat FIRE at a comfortable one and a much larger number. Coast FIRE means saving enough early that growth alone reaches your number by normal retirement age, so you only need to cover current costs.
: The savings rate matters most: spending less both raises what you save and lowers the number you need. Going from saving 20% of income to 50% cuts the working years far more than an extra percentage point of return.
: The retirement page works backwards from spending to the monthly saving you need. This one works forwards from your savings plan, in two phases, to the corpus you will have, and checks it against a FIRE number and a runway.