DPO (days payable outstanding) is the average days you take to pay suppliers. A DSO much longer than DPO means you are funding the gap from your own cash.

Cashflow Gap Calculator

By FundTap Team ·19 May 2026

TL;DR: Enter your accounts receivable, days sales outstanding (DSO), accounts payable, days payable outstanding (DPO), and monthly operating costs. The calculator returns your working capital gap and a practical recommendation. All numbers stay client-side: nothing is sent to FundTap.

Your numbers

Accounts receivable ($) Total invoiced and unpaid right now DSO — days to be paid Average days customers take Accounts payable ($) Total you owe suppliers DPO — days you take to pay Average days you pay suppliers Monthly operating costs ($) Wages, rent, software etc Cash on hand ($) Current bank balance

How the calculation works

The working capital gap formula used here is:

Gap = (Accounts payable + Operating costs over DSO period) - Accounts receivable - Cash on hand

It assumes your AR arrives in one lump at the end of the DSO period, and your AP plus operating costs flow out continuously. That is a simplification but it is the right shape for assessing whether you have a working capital problem.

What to do with the result

Healthy gap (negative or near zero): you have a buffer. If you are planning growth, model the gap with 20 to 30 percent more AR and see if you still have headroom.
Gap less than 1 month opex: tight but manageable. Fund 1 to 2 invoices to smooth the cycle. Avoid taking on fixed debt for what is fundamentally a timing problem.
Gap exceeds 1 month opex: needs immediate action. Most AU and NZ SMEs in this state delay supplier payments and accumulate stress that becomes a worse problem in 60 to 90 days. Invoice finance is the fastest fix because the funding is secured against the invoice, not your business.

Frequently asked questions

What is DSO and how do I calculate mine?

DSO (days sales outstanding) is the average number of days between when you issue an invoice and when the customer pays. Most accounting software (Xero, MYOB, QuickBooks) calculates this for you in the aged-receivables report. Industry averages: construction 60-90 days, professional services 30-60 days, retail 7-30 days, staffing/recruitment 30-60 days.

What is DPO?

DPO (days payable outstanding) is the average days you take to pay your own suppliers. If your DSO is much longer than your DPO, you are funding the gap from your own cash — that is the working capital problem invoice finance solves.

Is this calculator accurate enough for real decisions?

The calculator is a quick check. For investment decisions, build a 12-month cashflow forecast using your accounting software (most have built-in forecasting), and stress-test for 20 percent revenue growth and 30 percent delayed payment. If even one scenario puts you in critical territory, you have a working capital exposure worth addressing.

The work's done. The money shouldn't be the wait.

Get started See how it works

4.9 250+ reviews

Cashflow Gap Calculator

Your numbers

Your working capital position

Recommendation

How the calculation works

What to do with the result

Frequently asked questions

Cashflow Gap Calculator

Your numbers

Your working capital position

Recommendation

How the calculation works

What to do with the result

Frequently asked questions

Keep reading

Getting Your Cashflow Right After the Christmas Shutdown

Working capital for staffing and recruitment SMEs: why payroll cycles break cashflow and how to fix it

Common Cashflow Challenges In A Construction Business

Cashflow Forecasting for High-Growth Scenarios