About

Financial Independence, Retire Early (FIRE) is not just about saving; it is about reaching a mathematical crossover point where the passive returns from invested capital exceed living expenses. The standard model relies on the "4% Rule" (Safe Withdrawal Rate), but individual circumstances require stricter precision.

This tool projects the growth of your net worth against the eroding force of inflation and taxes. Unlike simple compound interest calculators, it solves for time: exactly how many years remain until work becomes optional. It forces the user to confront the "Gap" - the difference between income and spending, which is the primary driver of wealth accumulation.

Formulas

The FIRE Number is calculated based on annual expenses and the Safe Withdrawal Rate (SWR):

FIRE_num = ExpensesSWR

Future Value with monthly contributions is projected iteratively:

FV = P × (1+r)^t + PMT × (1+r)^t − 1r

Reference Data

Asset Class	Avg. Nominal Return	Inflation Adj. (Real Return)	Risk Profile
S&P 500 (Stocks)	10%	7%	High Volatility
Corporate Bonds	5%	2%	Moderate
HYSA / Cash	4%	1%	Low / Safe

Frequently Asked Questions

Originating from the Trinity Study, it suggests you can withdraw 4% of your portfolio annually (adjusted for inflation) with a very low risk of running out of money over a 30-year period.

Yes, use the "Tax Drag" input. Investment gains are rarely tax-free. A 15-20% capital gains tax reduces your effective compounding rate, extending your working timeline.