Personal
The only three numbers in personal finance
Budgeting apps show you two hundred figures. Almost every decision a household actually makes turns on three of them, and most people cannot name their own.
Ask someone what they spent on groceries last month and they will guess within twenty dollars. Ask them their net worth and you get a pause, then a range wide enough to drive a car through. We have built an entire category of software that is extremely good at the question that does not matter much and quiet about the three that do.
The first is net worth: everything you own minus everything you owe, measured monthly. Not because the number itself is interesting — on any given day it is mostly noise from markets you do not control — but because its slope is the only honest scoreboard for whether the last twelve months went the way you think they did. Income can rise while net worth flattens. That is worth knowing early rather than at fifty.
The second is free cash flow: what is left after everything, including the bills that arrive quarterly and the ones that arrive annually and the ones you have mentally classified as unusual for six years running. Most households compute this optimistically by leaving out the lumpy items, then wonder why the surplus never appears in the account. Take a full year, divide by twelve, and use that number instead. It is smaller and it is real.
The third is your savings rate: free cash flow as a percentage of take-home pay. This is the one that actually predicts outcomes, because it is scale-free. It lets you compare this year to last year after a raise, and it is the only one of the three you can move deliberately in a single month.
What makes them useful together is that they answer different questions. Savings rate tells you whether the machine is working. Free cash flow tells you what you can commit to — a mortgage payment, a car, a tuition bill. Net worth tells you whether the first two have been true for long enough to matter yet.
The house question is the clearest case. Nobody can answer whether you can afford a given price from your salary alone, because salary is not the constraint. The constraint is what monthly payment survives inside your real free cash flow after taxes, insurance, maintenance and the fact that a house generates its own expenses. Run it against the honest number and the answer usually arrives in under a minute, in one direction or the other.
None of this requires a budget in the sense most people mean — the envelope system that gets abandoned in week three. It requires knowing three numbers and watching their trend. If your money app cannot tell you all three in one screen, it is showing you the wrong two hundred figures.
DisclosureThis article is general information, not investment, tax or legal advice, and does not account for your circumstances. Tax rules change and apply differently to different households. Speak with a qualified professional before acting on anything here. All figures and examples are illustrative placeholders created for design purposes. Full disclosures.