Cash flow forecast calculator

See how your cash balance moves and whether you run short.

Use a minus sign if the account is overdrawn.

Cash you expect to receive, not invoices sent.

Salaries, rent, stock, tax and loan repayments.

Cash after 12 months

R 103 413

Lowest balance
R 40 000
Month of the lowest balance
Now
Months below zero
0

Estimates only. Not financial advice.

Cash balance by month

Month by month

Cash flow forecast
MonthOpeningInOutClosing
1R 40 000R 60 000R 55 000R 45 000
2R 45 000R 60 600R 55 550R 50 050
3R 50 050R 61 206R 56 106R 55 151
4R 55 151R 61 818R 56 667R 60 302
5R 60 302R 62 436R 57 233R 65 505
6R 65 505R 63 061R 57 806R 70 760
7R 70 760R 63 691R 58 384R 76 068
8R 76 068R 64 328R 58 967R 81 428
9R 81 428R 64 971R 59 557R 86 843
10R 86 843R 65 621R 60 153R 92 311
11R 92 311R 66 277R 60 754R 97 834
12R 97 834R 66 940R 61 362R 103 413

How the cash flow forecast calculator works

Last updated 10 November 2026

Profitable businesses still run out of cash when customers pay late. A forecast shows the problem before it arrives.

How it works

  • Closing balance = opening balance + money in − money out.
  • Money in and out change each month by the growth rates you enter.

Worked example

With the starting figures:

  1. With the starting figures cash ends at R 103 413.
  2. The lowest balance is R 40 000 in month 0.

Profit is not cash

A business can show a profit on paper and still run out of money. Customers pay late, stock is bought before it is sold and big bills arrive in a single month. A cash flow forecast shows what is likely to be in the bank month by month, so a shortage is visible before it happens.

What you enter

  • Your opening balance
  • Money coming in each month, such as sales and other income, and how fast it grows or falls
  • Money going out each month, such as rent, salaries, stock and loan repayments, and how it changes
  • The number of months to look ahead

Reading the forecast

The table shows the opening balance, money in, money out and the closing balance for each month. The chart shows the closing balance over time. The lowest balance, and the month it happens, is the number to watch. If it drops below zero, you would need a buffer, a loan or a change in timing to cover that month.

Things that are easy to forget

  • Annual or quarterly bills such as insurance, licences and tax payments
  • Loan repayments and interest
  • Customers who pay later than their terms say
  • VAT collected and paid over, if you are registered
  • Your own pay, which is a real cost to the business

Be careful with the inputs

The forecast is only as good as the inputs. Be cautious with income and generous with costs, then test a worse case by cutting income or delaying payments. The tool uses steady monthly growth rates, so it will not show seasonal swings unless you adjust the figures. Nothing you enter is saved.

Things to watch

  • Be cautious with income and generous with costs.
  • Include tax, loan repayments and annual bills, which are easy to forget.

Test different growth rates to see how sensitive the result is. Read the full disclaimer.

Questions people ask

What is cash flow?

It is the money actually moving in and out of your bank account, which can differ from profit because of timing.

What should I count as money in?

Cash you expect to receive in the month, not invoices you have sent but not been paid for.

Break-even calculatorHow many units you must sell to cover your costs, and to reach a profit.Profit margin calculatorProfit margin from cost and price, or the price needed for a margin.Monthly budget plannerList your income and spending, see what is left, and download or print the result.

Estimates only. Not financial advice. Read the full disclaimer.