Free tool · no signup

Free FIRE Calculator (Financial Independence, Retire Early)

Calculate your FIRE number, savings rate, and projected retirement age.

Calculator (no login required)Save your inputs →

What this calculator does

Calculates your FIRE number (annual expenses × 25, the 4% rule), shows your savings rate as a percentage of after-tax income, and projects how many years until you hit financial independence at your current pace.

How it works

  1. 1

    Enter income and expenses

    After-tax monthly income and average monthly expenses.

  2. 2

    See your savings rate

    The single most important number. 50%+ savings rate = FI in ~17 years from $0.

  3. 3

    Calculate FIRE number

    Annual expenses × 25 (the 4% safe withdrawal rate). Some people use ×33 for 3% to be more conservative.

  4. 4

    Project years to FI

    Compound growth at your assumed return (default 7% real) projects when your invested assets reach the FIRE number.

  5. 5

    Adjust assumptions

    Try different return rates, expense levels, and one-time windfalls to see how each shifts your timeline.

Want more?

Sign up free to save your inputs and unlock AI coaching

Free 30-day trial of every Blacknave app — including the full Net Worth + FIRE Planner with cross-device sync, history charts, and AI coaching that reads your data.

Start free trialSee Net Worth + FIRE Planner

Common questions

What is a FIRE number?▾
The portfolio size that lets you safely retire and live off withdrawals indefinitely. Most commonly calculated as annual expenses × 25, based on the Trinity Study finding that a 4% withdrawal rate has historically lasted 30+ years.
Is the 4% rule still safe?▾
It has held up across most 30-year periods in US market history including the Great Depression. More conservative variants use 3% or 3.5% (multiply expenses by 33 or 28). For early retirees with 40-50 year horizons, 3.5% is the modern conservative consensus.
What return rate should I assume?▾
For long-term US stock returns minus inflation, 7% real is the conventional planning number (S&P 500 has averaged ~10% nominal, ~3% inflation). For globally diversified portfolios with bonds, 5-6% real is more conservative.
How much does savings rate matter?▾
Savings rate is THE variable. Mr Money Mustache's table is canonical: 10% saved = 51 years to FI, 30% = 28 years, 50% = 17 years, 70% = 9 years. Income matters but savings rate matters more.

More free tools

TDEE Calculator (Mifflin-St Jeor + activity multiplier)Macro Calculator (protein, carbs, fat from your TDEE)Debt Payoff Calculator (avalanche vs snowball)