Net worth is the simplest number in personal finance — everything you own minus everything you owe — and also the easiest one to get wrong. The cash and brokerage accounts are trivial: log in, read the number. The trouble starts with the assets you can’t sell by Friday: your house, your 401(k), your car, maybe a small business. Skip them and your net worth is meaningless. Value them carelessly and it’s fiction in the other direction.
Here’s a method for including illiquid assets that stays honest.
The Core Formula, and Where People Go Wrong
Net worth = total assets − total liabilities. Two mistakes account for most bad calculations:
- Leaving illiquid assets out entirely. For many households, home equity and retirement accounts are the two largest line items. A net worth figure without them isn’t conservative — it’s just wrong, and it makes decisions like “can I afford to retire early?” impossible to reason about.
- Valuing them at fantasy prices. The opposite failure: counting your home at the neighbor’s peak-market sale price, or your car at what you paid for it. Illiquid assets belong in the calculation, but at defensible values.
The discipline that solves both: every asset gets a valuation method and an update frequency, decided once and applied consistently.
A Valuation Method for Each Asset Type
This table is the heart of the system. Pick your method per asset class and stop re-deciding every quarter:
| Asset | How to value it | Update frequency | Common mistake |
|---|---|---|---|
| Cash & savings | Account balance | Monthly | None — this one’s easy |
| Brokerage accounts | Current market value | Monthly | Ignoring taxes due on gains |
| 401(k) / IRA | Current account balance | Quarterly | Forgetting old employer plans |
| Primary home | Recent comparable sales, or online estimate minus ~6-8% selling costs | Annually | Using list prices, not sold prices |
| Rental property | Comparable sales or income-based appraisal | Annually | Skipping selling costs and repairs |
| Vehicles | Private-party value from a pricing guide (e.g., KBB) | Annually | Using original purchase price |
| Small business | Conservative multiple of earnings, or professional valuation | Annually | Valuing your own business optimistically |
| Collectibles / other | What similar items actually sold for | Annually or on sale | Insurance value ≠ market value |
Two conventions worth adopting from that table: haircut real estate by realistic selling costs (agent commissions and closing costs commonly run several percent of the sale price), and value vehicles at what a private buyer would pay today, not what the dealer charged you.
Real Estate: Count Equity, Not Price
Your house contributes equity to net worth, not its sticker value. The math, with illustrative numbers:
- Estimated market value: $400,000
- Minus estimated selling costs (~7% in this example): −$28,000
- Minus mortgage balance: −$250,000
- Equity contributed to net worth: $122,000
For the market value input, free online estimates are fine for a quarterly pulse, but they can be off meaningfully in either direction. Once a year, sanity-check against actual sold prices for comparable homes nearby. A professional appraisal (a few hundred dollars) is worth it before decisions that hinge on the number — refinancing, retirement planning, or a divorce or estate situation.
The mortgage side is easy to get exactly right — your servicer publishes the payoff balance — so don’t estimate it.
Retirement Accounts: Include Them, But Know the Asterisk
Your 401(k) and IRA balances belong in net worth at full current value — that’s the standard convention, and it’s what every net worth tracker does. But keep two mental footnotes:
- Traditional (pre-tax) balances carry an embedded tax bill. A $500,000 traditional 401(k) will not deliver $500,000 of spendable money; withdrawals are taxed as ordinary income. Some people track a second, “after-tax” net worth line that discounts pre-tax balances by their expected retirement tax rate. Whether that discount should be 10% or 30% depends on your situation — a question for a tax professional, not a blog post.
- Early-withdrawal penalties exist but don’t belong in the valuation. You’re measuring what you own, not what you’d net in a fire sale.
Also: hunt down old employer plans. Orphaned 401(k)s from previous jobs are one of the most common missing line items, and consolidating them (or at least listing them) can change the picture materially.
Liabilities: The Complete List
Understated debts inflate net worth just as effectively as inflated assets. The full sweep: mortgage and HELOC balances, auto loans, student loans, credit card balances (even if you pay in full — count the current statement balance), personal loans, buy-now-pay-later plans, and money owed to family. A free credit report is a decent audit tool for catching debts you’ve mentally filed away.
Tools: Spreadsheet vs. App
Both work; they fail in different ways.
Apps — Empower Personal Dashboard and Monarch Money are the strongest for net worth specifically. Both sync bank, brokerage, and retirement accounts automatically and let you add manual entries for real estate and vehicles (Empower can link a home-value estimate; both accept manual valuations). Copilot Money does this well too if you’re on iPhone/Mac. The failure mode: manual assets go stale because nothing forces you to update them. (If you’re coming from Mint, which shut down, Monarch and Empower are the natural successors.)
Spreadsheets — one row per asset/liability, one column per quarter. You control the valuation logic completely — the selling-cost haircut, the optional after-tax view — and you build a history you own. The failure mode: you stop updating it. A recurring calendar reminder fixes that.
A sensible hybrid: let an app sync the liquid accounts daily, and keep a quarterly spreadsheet snapshot where you apply your valuation rules to the illiquid entries.
Track the Trend, Not the Level
The single most useful thing about a rigorous net worth number is watching it move. Quarter over quarter, the direction and slope tell you whether your saving, investing, and debt payoff are actually compounding — and unlike the individual asset values, the trend is robust to small valuation errors, as long as you apply the same method every time. That’s the real payoff of the consistency rule: change your valuation method mid-stream and you can no longer trust the chart.
Set a quarterly date, update the numbers, and note one sentence about what drove the change. Twelve of those entries later, you’ll have something almost nobody has: an honest, longitudinal picture of your financial life — illiquid assets included, fantasy excluded.