Net Worth Tracker: Know Your Number and Your FIRE Date

Target keyword: net worth tracker spreadsheet

Meta description: Compute your net worth from assets and liabilities, track it monthly, and see how your savings rate maps to financial independence — one number, one habit, one date.

Reading time: ~7 minutes

Net worth is the one number that summarizes your entire financial position: everything you own minus everything you owe. It doesn't care how much you earn. A $200k earner with $180k of debt has less wealth than a $70k earner with a paid-off house and a brokerage account. Income is a flow; net worth is the stock it builds — and flows are easier to fool yourself about.

Tracking it monthly is a small habit with a disproportionate effect. The month-by-month series tells you whether your money decisions are working before the feeling of "doing fine" gets a chance to lie to you. And once you know your number and your savings rate, you can estimate the number most people never compute: the date your investments could support you — your FIRE date.

How to compute your net worth

The formula is one line: net worth = assets − liabilities.

Assets are things you own that have value: checking and savings balances, investment and retirement accounts, your home's current market value, vehicle value, and anything else you could sell. Use today's values, not what you paid.

Liabilities are what you owe: mortgage balance, car loans, student loans, credit card balances (the full balance, not the minimum), personal loans, anything with a payoff number. If the list is long, order the attack — snowball vs avalanche, computed on your numbers.

Subtract. The result might be negative — that's common early on, and it's exactly why the tracking habit matters: the trend line is the story, not any single month. A negative net worth that rises $2,000 a month is a plan working.

Why track it monthly (not daily, not yearly)

• Monthly is the right cadence. Daily tracking is noise — markets wiggle, and wiggle teaches nothing. Yearly is too slow to steer by. Monthly snapshots show the real slope of your finances: are you building, or drifting?
• It exposes silent leaks. When net worth growth stalls despite a steady income, the spreadsheet forces the question "where did it go" — and the answer is usually visible two clicks away in your spending.
• It reframes windfalls. A bonus or tax refund doesn't become lifestyle money when your habit is net-worth-first — it becomes a jump in the line. Same money, different story.

From net worth to your FIRE date

FIRE — financial independence, retire early — sounds like a lifestyle, but the math underneath is ordinary arithmetic. The core ideas:

• Savings rate is the master variable. The percentage of your income you save and invest determines your timeline more than your investment returns do. A higher savings rate buys years; a lower one costs decades.
• The 4% guideline. A common planning rule of thumb: a portfolio can sustain roughly 4% annual withdrawals over a long retirement. So your "FIRE number" is roughly 25× your annual spending. (It's a guideline built on historical market data, not a guarantee — treat it as a compass, not a contract.)
• Your FIRE date. Given your current investments, your monthly savings, and an assumed growth rate, you can project when your portfolio crosses that 25× line. The date moves as your savings rate moves — which is the motivational loop: saving more literally pulls the date closer, visibly.

Run the numbers once and they stop being abstract. The date on the screen changes how the next spending decision feels. The Net Worth + FIRE Dashboard projects that date from your own savings rate — enter your assets and liabilities once, and watch the date move as you save more.

Frequently asked questions

Should I include my home in net worth? Yes for the honest number — it's an asset you own minus a liability you owe. Some people also track a separate "investable net worth" that excludes home equity, since you can't easily spend a house. Track both if you want; the habit matters more than the definition.

Isn't this depressing if the number is negative? Only if you read it once and stop. Read it monthly and the negative number becomes the most motivating thing on the page: it's proof of direction, not just position.

Does the 4% rule still hold? It's a rule of thumb from historical US market data, and like all rules of thumb it has critics and edge cases (sequence risk, taxes, inflation). Use it as a planning compass — the value of computing a FIRE date is having a target at all, not having a perfect one.

*The Poisefolio Net Worth + FIRE Dashboard ($3.99) does the whole job: enter your assets and liabilities, watch your monthly net worth series build, and project your financial-independence date from your savings rate. Works in Excel and Google Sheets. Use code NEXT10 for 10% off — no expiry, no games.*

*Planning tool, not financial advice. The 4% guideline and FIRE projections are planning estimates built on historical market data; your actual results will differ and are not guaranteed.*