METHOD & GUIDANCE
How this calculation works
Keep every input on the same time basis—for example, one month or one financial year—and do not mix cash figures with accrual figures. Tool IQ recalculates every output immediately; nothing you enter is saved or sent to us.
How to use the result
Enter cash when it is expected to reach or leave the bank, not when an invoice is raised. Compare the base forecast with a delayed-receipts case and decide the minimum closing-cash buffer before committing spend.
Worked example
The opening case starts with £40,000, adds £65,000 of receipts and subtracts £55,000 of operating, payroll and tax payments plus a £3,000 one-off outflow. Forecast closing cash is £47,000.
Common mistakes
- Using sales invoices as if they were cleared cash receipts.
- Leaving VAT, payroll, loan payments or one-off costs outside the forecast.
- Treating one positive closing balance as proof that every week in the period remains liquid.
Frequently asked questions
Is the cash flow forecast calculator free?
Yes. It requires no account and stores no calculation inputs.
Can I use the answer for a formal filing?
No. It is a planning estimate, not accounting, tax, legal or investment advice. Confirm material decisions with a qualified professional.
Which period should I use?
Keep every input on the same basis—for example, one month or one financial year. Use current figures first, then save a cautious scenario for comparison.
Should an unpaid invoice be entered as a receipt?
Enter it only in the period when payment is realistically expected to clear. Run a second case with important receipts delayed.
Why can a profitable business still forecast low cash?
Profit and cash use different timing. Inventory, tax, payroll, loan repayments, capital spending and late customer payments can consume cash before related revenue is collected.
Continue the decision
- Cash Runway Calculator — Estimate how many months your available cash will last.
- Days Sales Outstanding Calculator — See how long customer invoices take to become cash.
- True Employee Cost Calculator — Estimate the full cost of hiring beyond headline salary.
Popular small-business decision paths
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Method reviewed 5 August 2026. Figures are illustrative and calculated locally in your browser. Official sources are linked where a rule or obligation affects how the result should be used. Read the Tool IQ calculation standard for our checking process, limitations and corrections policy.