Financial independence isn't a vague aspiration — it's a math problem. Your FIRE number is 25 times your annual expenses. Your freedom date is determined by how much you save and invest each month. FIRECalc Lite makes both numbers concrete so you can stop wondering when you'll be free and start building toward a specific date.

Slide your savings rate. Watch the years melt away. Find the number that makes freedom real.

How It Works

Enter your annual expenses, current savings and investments, annual income, and savings rate. FIRECalc Lite calculates your FIRE number automatically using the 25x rule, projects your freedom date based on your current savings rate, and shows you how changing your savings rate by 5% or 10% moves that date. The sensitivity table maps every combination of savings rate and expected return so you can see the full range of outcomes before committing to a plan.

Compare Lean FIRE, Regular FIRE, and Fat FIRE side by side — three different expense levels, three different FIRE numbers, three different freedom dates — so you can choose the lifestyle target that fits your goals.

Enter your annual expenses, current savings, income, and savings rate
Review your FIRE number and projected freedom date
Adjust your savings rate and watch the freedom date change
Compare Lean, Regular, and Fat FIRE paths side by side
Use the sensitivity table to stress-test different return assumptions

Who It's For

FIRECalc Lite is built for anyone pursuing financial independence who wants to see their FIRE number and freedom date clearly — not as a rough estimate, but as a calculated target. It's the right fit if you:

Are pursuing FIRE and want to know your exact number and projected freedom date
Want to see how increasing your savings rate by 5% or 10% changes your timeline
Are deciding between Lean, Regular, and Fat FIRE and want to compare the numbers
Want to stress-test your plan against different market return assumptions
Want a one-time calculator you own forever, not a subscription tool

It's a planning and projection tool, not a portfolio tracker. For tracking your actual investment accounts and net worth progress toward your FIRE number, use NorthStar Net Worth alongside FIRECalc Lite.

What's Included

FIRE Number Calculator — automatic 25x calculation based on your annual expenses
Freedom Date Projector — projected date of financial independence at your current savings rate and expected return
Savings Rate Sensitivity Slider — adjust your savings rate and see the immediate impact on your freedom date
Lean / Regular / Fat FIRE Comparison — three expense levels, three FIRE numbers, three freedom dates side by side
Sensitivity Table — full matrix of savings rates vs. return assumptions showing the range of possible freedom dates
Safe Withdrawal Rate Calculator — confirms your FIRE number supports your target annual spending at a 4% withdrawal rate

Instant digital download. After purchase, you'll receive a link to copy the Google Sheet directly to your Google Drive. No software to install, works on any device.

Frequently Asked Questions

What is a FIRE number?
Your annual expenses x 25. At that portfolio size, you can withdraw 4% annually and — based on historical data — your portfolio should last indefinitely.

What's the difference between Lean, Regular, and Fat FIRE?
Lean = frugal lifestyle (~$40K/year). Regular = comfortable middle-class (~$50–$80K/year). Fat = high-spending retirement ($100K+/year). FIRECalc shows the number and freedom date for all three.

What is the 4% safe withdrawal rate?
From the Trinity Study: a portfolio can sustain 4% annual withdrawals for 30+ years in nearly all historical scenarios. It's the foundation of FIRE math and the basis for your FIRE number.

How does the sensitivity table work?
Maps every combination of savings rate and expected return, showing the resulting freedom date. Stress-test your plan against different market scenarios at a glance.

Is this a subscription?
One-time purchase. Copy it to your Google Drive and own it forever. No fees, no account, no renewal.

FIRECalc Lite – FIRE Number Calculator Google Sheets