Estimate your financial independence number, years to FIRE, and target date from spending, savings, return, inflation, and withdrawal assumptions.
When to use this
Use it before a FIRE target turns into a slogan
A FIRE number is only useful when the spending, savings rate, return, inflation, and withdrawal assumptions are explicit. Use this as a first-pass map before deeper planning.
Default result
The server-rendered starter example reaches $1,224,000 in 19 years 1 month, around July 2045.
Result interpretation
What the FIRE number means
The target is a spending multiple
A lower withdrawal rate raises the target. Higher annual spending raises the target. The cushion is added on top, not withdrawn annually.
The date depends on real return
Because the target is in today-dollar spending, the timeline uses return after inflation. Lower real return can move the date by years.
Ready is not the same as safe
Taxes, health insurance, sequence risk, asset allocation, fees, and flexible spending rules matter before any early-retirement decision.
Worked example: 19 years to FIRE
With $48,000 of annual spending and a 4% withdrawal rate, the base FIRE number is $48,000 / 0.04 = $1,200,000. Adding a $24,000 cushion makes the target $1,224,000.
Starting with $150,000 leaves a $1,074,000 gap. A 7% nominal return and 2.5% inflation gives a real return of (1.07 / 1.025) - 1 = 4.390%. The monthly real return is about 0.3587%.
Projecting $150,000 plus $2,500 per month at that monthly real return reaches the $1,224,000 target after 229 months, or 19 years and 1 month, around July 2045 from the June 2026 example date.
How much money do I need for FIRE?
Use annual spending after financial independence, not gross income. The core target is annual spending divided by the withdrawal rate. At 4%, the spending multiple is 25x before any extra cash cushion.
How many years until financial independence?
The calculator projects the current portfolio and monthly contributions with the entered real monthly return. It stops when the projected portfolio reaches the FIRE number, or reports no finite date within 100 years.
How monthly savings changes your FIRE date
Monthly savings matters because it both closes the gap and gives each contribution time to compound. The 10-year monthly need card shows the contribution required to hit the current target in exactly 120 months under the same return assumptions.
Why the 4% rule is only a planning assumption
Bengen describes the historical origin of the simplified 4% rule and notes that it was built from historical data, not a promise about the future. Early retirement, taxes, fees, long horizons, and changing spending can all require a different withdrawal plan.
How to make a shareable FIRE result
Use the copy button to share the target, estimated date, and assumptions. The shared text includes a Useful Atlas link so another person can calculate their own version instead of copying your private details.
Reference data
Sources and assumptions
Topic
Value used
Source
Date
Note
Compound growth inputs
Initial investment, monthly contribution, time horizon, estimated interest rate, and compounding frequency
The calculator mirrors the same planning variables but uses real-return monthly growth for FIRE timing. Verify current SEC educational material on the source.
4% rule background
Bengen describes a 4.15% initial withdrawal rate that historically lasted at least 30 years in his data, later simplified as the 4% rule
This is a planning shortcut, not a guarantee or personalized investment advice. The withdrawal-rate input is editable.
FAQ
What is a FIRE number?
A FIRE number is the portfolio amount that could support a target level of annual spending under a chosen withdrawal-rate assumption. This calculator uses annual spending divided by withdrawal rate, then adds any cash cushion you enter.
Is the 4% rule safe for early retirement?
Not automatically. The 4% rule came from historical retirement withdrawal research and is often discussed around 30-year retirements. Early retirement can require a longer horizon, flexible spending, taxes, health-care planning, and lower or variable withdrawal assumptions.
Does this calculator include taxes?
No. It estimates a pre-tax planning target. Taxes, account type, health insurance, debt, housing, social security, pensions, and market sequence risk can change the real answer materially.
Why does the calculator use real return?
The FIRE target is entered in today-dollar spending. A real-return estimate removes the entered inflation rate from the nominal return so the timeline stays in current purchasing-power terms.
What happens if my return is lower than inflation?
The monthly projection can still reach the target if contributions are high enough, but the timeline lengthens. If the entered savings and return never reach the target within 100 years, the result says no finite date.
Can I share my FIRE result?
Yes. The copy button creates a short text summary with the target, estimated date, core assumptions, and a Useful Atlas link so someone else can calculate their own version.
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