Cash flow calculator

Cash flow is the money moving in and out of the business. Net cash flow is cash in minus cash out, including spending on equipment, for the period.

The formula

Cash flow = cash in − cash out − capital spending

Worked example: −£9,000 a month

The example is a UK software company in one month: £50,000 of revenue excluding VAT, 400 customers and £180,000 in the bank.

£48,000 in − £55,000 out − £2,000 equipment = −£9,000

Work out your cash flow

Until you type a figure, the results show an example business. Fill in only what you know: from then on every result uses your figures alone, and nothing you type leaves your browser.

Your business numbers

Start with any one figure. Until you do, the results show the example business, whose figures are the grey hints in each box.

What this calculation uses

MonthQuarterYear

Equipment and other capital spending

Things that last more than a year.

Cash in the bank

Cash received from customers (needed)

In the period, not what you invoiced.

Cash paid out for running costs (needed)

In the period, not counting equipment.

Add more of your numbers

Open a group to fill it in. Everything you add shows up in the list below the calculator.

Sales and VAT

Turnover

Everything you invoiced in the period.

My turnover includes VAT

20%5%None

VAT you reclaim on costs

Input VAT on your purchases in the period.

Of which recurring

Subscriptions and contracts, excluding VAT.

Value of orders through your platform

Marketplaces only: what buyers paid in total.

Costs

Cost of sales

Costs that grow with each sale: materials, hosting, payment fees.

Staff costs

Salaries, employer National Insurance, pensions, freelancers.

Sales and marketing

Ads, sales salaries and tools.

Other running costs

Rent, software, insurance, admin.

Depreciation and amortisation

From your accounts. 0 if you have none.

Interest paid

Corporation Tax

For the period, if you pay any.

Customers and orders

Customers at the start

New customers

Customers lost

Number of orders

Or invoices, for a service business.

Recurring revenue over one month

MRR at the start of the month

Upgrades

Extra MRR from existing customers.

Downgrades

MRR lost from customers who left

Growth

Turnover in the previous period

The month, quarter or year before, on the same basis as your turnover.

Turnover in the same period last year

Balance sheet

Everything the company owns

Cash, equipment, money owed to you.

Everything it owes

Loans, bills, tax due.

Team

Hours your team works a week

Everyone added together.

Full-time hours a week

One investment or campaign

What you spent

On a campaign, a hire or a piece of kit.

What it brought back

Extra gross profit it produced.

Net cash flow for the example

Example

−£9,000

a month

£48,000 in − £55,000 out − £2,000 equipment = −£9,000

Formula: Cash in − cash out − capital spending.

Cash at the end: £171,000; if £180,000 was the starting balance

Everything your numbers show

For the example business: 29 of 29. Type your own figures to replace them. Select one for its page.

How to read your result

A negative figure lowers your cash balance by that amount. Compare it with your forecast every month to spot problems early.

Watch out for

Plan for the VAT you will pay HMRC, so a quarter-end payment does not catch you out.

Last checked 24 October 2026. Estimates only, not financial, tax or legal advice: check your accounts and documents, and take advice before you act. More terms in the startup glossary.