See your cash position month by month before it happens: a starting balance, your recurring income and expenses, and the one-off bills and windfalls in between. The forecast flags your lowest balance and the first month you would dip below zero. Everything updates live in your browser; the defaults are the worked example.
The maths: each month, closing balance = last month’s closing + money in − money out. Recurring rows repeat every month; a one-off lands only in its month.
Money in and out include that month’s one-off items. A negative closing balance is highlighted — that is the month the account runs dry.
| Month | Money in | Money out | Net | Closing balance |
|---|
Month-by-month cash forecast from a starting balance, recurring income and expenses and one-off items — with the lowest point and the first negative month flagged.
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Project your bank balance month by month from a starting balance, recurring monthly income and expenses, and one-off items: a full month-by-month table of money in, money out, net and closing balance, your ending balance, the lowest point of the forecast, the average monthly net, and a clear warning naming the first month the account would go negative.
A freelancer starts with $5,000, earns $8,000 a month and spends $6,500, so the recurring net is +$1,500 a month and the 12-month ending balance is $5,000 + 12 × $1,500 = $23,000. Adding a one-off −$9,000 tax bill in month 3 drops that month’s closing balance to $500 (the forecast’s lowest point) and the ending balance to $14,000 — still positive, but with almost no headroom in month 3, which is exactly the month to plan around.
Each month, closing balance = previous closing balance + money in − money out. Recurring income and expense rows are summed and applied every month; a one-off item is added to the money in (positive amount) or money out (negative amount) of its single month only. The lowest closing balance, the first month with a negative closing balance and the average monthly net (total net ÷ number of months) are all read from that same month-by-month sequence, and the totals are the plain sums of the table columns.
The first month whose closing balance drops below $0 — the month the account runs dry on these numbers. The warning banner names it as soon as it appears, so you can act months ahead: chase invoices earlier, move a payment, or build the balance up before that month arrives.
It is your tightest moment in the whole forecast — the smallest cushion you will have. If the lowest closing balance is $500 in month 3, then month 3 is where an unexpected bill would hurt most, and it is the figure to compare against the buffer you want to keep.
Each one-off has a name, a signed amount and a month number. A negative amount is a one-time cost added to that month’s money out; a positive amount is a one-time receipt added to that month’s money in. It affects only that month’s row — the recurring rows carry on unchanged either side of it.
Because the average is taken over the whole forecast including one-off items. Recurring income of $8,000 and expenses of $6,500 give a recurring net of +$1,500, but a −$9,000 one-off pulls the 12-month average down to ($18,000 − $9,000) ÷ 12 = $750. Both figures are shown, labelled, so you can see the underlying run-rate and the real average separately.
You can, by listing every income and expense row for both in the one forecast — the maths only cares about totals per month. If the two have different starting balances, add them together for the starting balance. Keeping them as separate forecasts (run the tool twice) usually reads more clearly.
No. Everything is calculated live in your browser and nothing is uploaded or stored — refresh the page and the worked example returns. If you need a record, note the ending and lowest balances from the results panel.
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