FIRE Calculator

How this result is built

Turn annual spending and a withdrawal rate into a financial-independence target, then project savings toward it.

Financial independence, in this simple form, is a portfolio large enough that a withdrawal rate covers spending. At 4%, $60,000 of spending points at a $1.5 million target. The projection then asks whether your current savings and monthly investing arrive there on the timeline you typed.

What the opening example is for

The 4% figure comes from historical studies of US portfolios over 30-year retirements. A longer retirement, a lower equity share, or high fees can argue for a lower rate. The field is editable for that reason.

The walkthrough below uses the numbers already sitting in FIRE Calculator. Press Calculate and the headline should match this page. Then put your own figures in. The math does not run until you press the button, and Clear hides the result.

What each field is doing

The “Annual spending” line on FIRE Calculator starts at $60,000.00. The other fields stay put while you change this one. That is the clean way to see what this line is doing inside the result.

FIRE Calculator treats “Withdrawal rate” as its own entry, and the form opens with 4%. If the label is a rate, type the annual figure the contract uses. If it is money, type the amount that will actually move, not a rounded hope.

Before you replace it, “Invested now” reads $150,000.00 on FIRE Calculator. Leave that figure only when it matches the statement, the quote, or the plan you are testing. Press Calculate after the edit so the chart and the schedule move with it.

The remaining fields

Look at “Monthly investment” first if you are checking FIRE Calculator: the filled value is $2,000.00. A round example is useful for learning the page. It is a poor substitute for the number on your own paperwork, so replace it and run the form again.

The “Annual return” line on FIRE Calculator starts at 7%. The other fields stay put while you change this one. That is the clean way to see what this line is doing inside the result.

FIRE Calculator treats “Years to project” as its own entry, and the form opens with 15. If the label is a rate, type the annual figure the contract uses. If it is money, type the amount that will actually move, not a rounded hope.

The opening result, line by line

Press Calculate on the opening form and FIRE target is $1,500,000.00. That is the number the rest of this section is talking about.

Projected savings is $1,061,266.60 when you run the opening figures on FIRE Calculator. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

On this opening pass, gap is $438,733.40. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

How those lines were produced

FIRE Calculator reports that withdrawal rate is 4.00%. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

A 4% withdrawal is a research starting point from historical US markets, not a promise.

A second pass changes only “Annual spending”, from $60,000.00 to $66,000.00. FIRE target moves from $1,500,000.00 to $1,650,000.00. Nothing else on the form was edited, so the gap between those two results is the effect of that one field on FIRE Calculator. If the gap is tiny, this page is not very sensitive to that entry. If the gap is large, get that entry from a document before you plan around the result.

What this page will not claim

FIRE Calculator follows the contribution, the return, and the years you enter. It does not look up your income, a workplace-plan phase-out, or a custodian balance. The 2026 limits named on this desk are ceilings, not instructions to contribute the maximum.

FIRE Calculator stops at its own formula. When the next question is different, open Retirement Calculator (Savings at retirement, next to the nest egg spending implies.); Savings Calculator (What a monthly deposit becomes.); Investment Calculator (Starting balance plus a monthly contribution.). Do not add those results to this one as if they were the same kind of dollar.

Check the result before you use it

Start on FIRE Calculator by reading the labels, not the headline. The opening labels are Annual spending ($60,000.00), Withdrawal rate (4%), Invested now ($150,000.00), Monthly investment ($2,000.00), Annual return (7%), Years to project (15). If a label is not the fact you have, the result cannot turn into that fact later. The illustration on the form lands on $1,500,000.00. When you press Calculate and see that same figure, the button and this explanation are using one formula.

Change one field at a time. Write down the headline, edit a single line, and press Calculate again. A large jump means that line carries the result. A line that does not move is a line the formula ignores, which is a reason to confirm you opened the right page. FIRE Calculator is built for one job: The portfolio that covers spending at your withdrawal rate. The description on the page says the same thing in a sentence: Turn annual spending and a withdrawal rate into a financial-independence target, then project savings toward it.

When the paperwork disagrees

Then hold the headline next to a source outside the site. That source might be a loan estimate, an account statement, a pay stub, or the public limit named in the methodology. A few cents of difference on a long schedule is ordinary rounding. A different rate, a fee you never typed, or a tax the form does not ask for is not rounding. Correct the input. Do not average the page with the paperwork.

When the outside source still disagrees, FIRE Calculator has reached the edge of what it will claim. It will not phone a lender, pull a county record, or apply a credit you left blank. Send the calculator name, every input, and the result you expected through the contact page if you think the formula itself is wrong. Until that is settled, read $1,500,000.00 as the output of the fields above and nothing else.

FAQs