Personal Finance102 · Module I · Lesson 01 of 11
Article · 12 min

Net worth from first principles

What you own minus what you owe, and why the trend line is the point.

Summary

A household balance sheet is a list of what you own and what you owe on a single day. Net worth is the difference. It is the single most important number in personal finance because every other decision — how much to save, how much to invest, whether to buy a home — moves that number, and the direction of the movement is knowable in advance.

Objectives
  • 01List the standard asset and liability categories of a household.
  • 02Compute net worth from a set of accounts.
  • 03Distinguish gross from net worth and productive from consumptive assets.
The Lesson

Assets

Group assets into three tiers. Cash and equivalents: checking, savings, money-market funds, Treasury bills. Investments: brokerage accounts, retirement accounts, business equity. Use assets: primary residence, vehicles, personal property. The tiers matter because their liquidity and their volatility differ, and mixing them hides both risks.

Liabilities

Group liabilities by maturity. Short-term: credit-card balances, auto loans nearing payoff. Medium-term: student loans, car loans. Long-term: mortgage. Note the interest rate on each, because the weighted-average cost of your liabilities is the return you are guaranteed by paying them down.

Net worth, honestly

Subtract total liabilities from total assets. Do it once a quarter on the same day of the calendar. The trend line matters more than the absolute number, and the trend line is where the household's operating discipline shows.

Key Ideas
  • Net worth is the master metric. Everything else feeds it.
  • Quarterly cadence, same day of the calendar. The trend is the signal.
  • Liquidity tiers and liability maturities are separate concerns; do not blend them.
References
  • Federal Reserve, Survey of Consumer FinancesThe reference distribution of household balance sheets in the United States.