All the money models in this series watch a flow: the budget watches spending, the runway watches cash, the countdown watches the pension. Useful gauges, every one. But gauges aren’t the question. The question is: is the whole machine working? Are you, overall, getting ahead? — and no single account can answer it, because modern money is scattered across a dozen of them, some of which are debts.
The instrument that answers it is the oldest one in finance, scaled down to a household: a balance sheet. What you own, what you owe, and the difference — net worth — tracked over time. One page, one hour a quarter.
The sheet
Two Tables. Own: every asset with a real value — current account, savings, ISAs, pensions (the app you never open knows), the house at an honest estimate, the car at what it would actually fetch. Owe: every debt — mortgage balance (your amortisation table already knows it), loans, cards, student loan if it’s a real repayment for you. Then:
=SUM(Own[Value]) - SUM(Owe[Balance])
That’s it. That number — positive or negative, and especially its direction of travel — is the machine’s output gauge.
Three honesty rules keep it meaningful. Value things at what they’d fetch, not what they cost — the sofa isn’t £2,000, and mostly the sofa isn’t on the sheet at all; stick to things with a market. Count the pension even though it’s locked — it’s the retirement plan’s engine and usually the biggest line; watching it grow is half the point. Don’t skip the ugly rows — the card balance you’d rather not type is the row the sheet exists for.
The part that matters: the history
A single snapshot is mildly interesting. The time series is
the product. Add a Snapshots table — date, total assets, total
debts, net worth — and append one row per quarter (calendar
reminder; it’s ten minutes now the sheet exists). Then chart it:
net worth as the
one honest line, rising
or not.
The chart quietly teaches the two lessons every saver needs. Wobbles stop being frightening — the 2022-style dip that feels like catastrophe in an ISA app is a dent in a rising line here, because contributions and debt paydown kept working while prices fell. And debt repayment finally looks like progress — every overpaid £100 moves this number exactly as much as £100 saved, which no bank statement will ever show you. People who track net worth stop arguing about pots versus paydown emotionally; both feed the same line.
What it isn’t
The number is a gauge, not a scoreboard. It doesn’t measure your worth (terrible name), it moves with markets you don’t control, and comparing yours to anyone else’s ignores every circumstance that matters. Its one honest job is comparison with your own past — four dots a year, drawn from statements in an hour.
Quarterly, not daily: this is deliberately the anti-app. Money apps want engagement; the balance sheet wants perspective — the compounding chart’s timescale, not the news cycle’s. One page, four rows a year, one line that answers the only question the gauges can’t: it’s working. Keep going.