Cash Flow Calculator
See whether you will have enough cash each month. Enter the opening balance and one line per period with money coming in and going out. The calculator rolls the balance forward, shows each period’s net flow and closing balance, marks the lowest point and any periods below your safety buffer, and – if you are burning cash – the average burn and how many periods the money will last.
- Runs in your browser
- No sign-up
- Free to use
One line per period (month, week or quarter).
How to use Cash Flow Calculator
- Enter the opening cash balance.
- Add one line per period: name | in | out.
- Set a minimum buffer.
- Check the lowest balance and runway.
Cash Flow Calculator features
Rolling balance
Period by period.
Lowest point
When cash is tightest.
Buffer warning
Periods below your minimum.
Burn and runway
For loss-making periods.
Paste from spreadsheets
Tab or | separated lines.
Any currency
Choose from 30+ currencies; amounts are formatted for it.
When to use Cash Flow Calculator
- Small business cash planning.
- Startup runway checks.
- Seasonal businesses.
- Freelancers with irregular income.
Cash Flow Calculator FAQ
Why is cash flow different from profit?
Profit counts sales when they happen; cash flow counts money when it arrives. Late-paying customers can make a profitable business run out of cash.
What is runway?
How long the current cash lasts at the average net burn.
Can I use weeks instead of months?
Yes. Each line is one period of any length.
What buffer should I keep?
Many small businesses aim for one to three months of costs.
Planning for the lowest point
The month with the lowest balance is the one to plan for: that is when a late payment or an unexpected bill could cause trouble. Knowing it in advance leaves time to arrange credit, delay a purchase or chase invoices.
Update the forecast with actual figures each period, so the projection stays realistic.
Re-run the numbers whenever an input changes – a supplier raises prices, a fee is updated or demand shifts – because small changes in costs or volumes often have a large effect on the result.
The calculator is deliberately simple: it uses the figures you enter and shows the arithmetic, so you can follow every step and repeat it in a spreadsheet when you want to build a fuller model.