List what comes in and what goes out, line by line, and see your net monthly cash flow, the balance twelve months ahead, and the month you would hit zero. Saved in your browser only — nothing leaves this page.
The arithmetic under the ledger
net cash flow = money in − money out
next month's balance = this month's balance + net cash flow
Two lines, applied twelve times. The reason to itemize rather than estimate is that aggregates hide the levers: “we spend €10,750 a month” suggests nothing, while a ledger showing payroll, rent, software and ads as separate lines shows exactly where a cut or a raise would land. One-off items get their own cadence because treating a single project payment as recurring income is the fastest way to build a picture that flatters you — the tracker lands one-offs in the current month and lets the recurring lines carry the projection.
When the recurring net is negative, the balance line becomes a countdown, and the months until it crosses zero are your runway. That single number deserves more attention than the rest of the ledger combined — the cash runway calculator works it against your real burn, and when will you run out of cash covers what actually moves it. If the ledger keeps coming out negative and you want the causes rather than the arithmetic, the cash flow problems guide names the usual five.
Tracking or forecasting: which one you need
Tracking and forecasting get conflated because both end in a balance projection, but they answer different questions. Tracking is itemized and present-tense: which lines, how much, what net they produce — this page. Forecasting is aggregate and future-tense: given monthly totals and a growth assumption, where does the balance go — the cash flow forecast's job, including the growth compounding this ledger deliberately leaves out. Start with tracking; the totals a forecast needs are what a maintained ledger produces.
Both run at monthly grain, which is right until cash gets tight. Inside a hard month, the order of payments matters as much as their sum — payroll on the 25th with the big invoice landing on the 28th is a crisis a monthly view cannot see. That is what the 13-week cash flow forecast exists for: the same arithmetic at weekly grain, over the quarter where you can still act. The habit that keeps any of these honest is a fixed monthly business review — thirty minutes, same day each month, ledger first.