Break-even point: the one number every new business should calculate before launch

It's a strikingly common gap: founders who can describe their product, their customer and their marketing plan in detail, but who've never actually calculated the one number that tells them whether the whole thing can work — the break-even point, the volume of sales needed just to cover costs, before a single pound of profit appears.

Why this matters before launch, not after

Calculated early, break-even is a planning tool — it tells you whether the volume of sales required is remotely realistic given your actual market, and it forces an honest look at pricing and costs before either is locked in by momentum.

Calculated after launch, once premises are leased and stock is bought, it's just an uncomfortable fact you now have to live with rather than a decision you can still change. By then the fixed costs are already committed, and the only lever left is working harder to hit a number that a five-minute calculation would have flagged as unrealistic months earlier.

If you don't know your break-even number, you don't actually know whether your business plan works. You know that it sounds plausible, which is a different thing entirely.

How to actually calculate it

Add up your fixed costs for a typical month — rent, salaries, subscriptions, anything you pay regardless of how much you sell. Work out your gross margin per sale — price minus the direct cost of delivering it.

Divide fixed costs by that margin, and you have the number of sales needed each month just to break even. It's a rough calculation, not a precise science, but a rough calculation genuinely done beats a plan that's never run the numbers at all. Most spreadsheet templates for this take under half an hour to fill in properly.

A worked example

Say you're planning a small café. Rent, rates, insurance, a part-time wage and the loan repayment on the fit-out come to £4,800 a month in fixed costs, whatever you sell. Your average sale is £4.50, and the ingredients, packaging and card processing fee behind it cost £1.50, leaving a gross margin of £3 per sale. £4,800 divided by £3 is 1,600 — that's 1,600 sales a month, or roughly 53 a day across a six-day week, just to cover costs before a single pound of profit appears.

Whether that number is realistic depends entirely on the foot traffic, seating and opening hours you can honestly expect — and this is exactly the point of doing the sum before signing the lease, not after. Fifty-three transactions a day is comfortably achievable for a busy high-street unit with good footfall; it's a genuinely difficult number for a quiet side street with limited passing trade, however good the coffee is. The maths doesn't care how good the coffee is.

The mistakes that make the number lie to you

The most common one is leaving the owner's own pay out of fixed costs entirely — treating your own time as free because you're not technically drawing a salary yet. That produces a break-even number that looks achievable but only works if you're prepared to work for nothing indefinitely, which isn't really a break-even point at all, just a deferred one.

The second is ignoring seasonality by using an average month. A business that does most of its trade in the run-up to Christmas, or in the summer months, needs to know its break-even point for its quietest month too, not just its average one — that's the month that actually determines whether the business survives its first year.

The third is forgetting VAT. If you expect to cross the £90,000 VAT registration threshold within your first year, build that into the model now, because the sales volume needed to cover the same fixed costs changes the moment registration becomes compulsory — it's a far easier adjustment to plan for in a spreadsheet than to discover the month it happens to you.

What to do once you have the number

Ask honestly: is that volume realistic given your actual market size and marketing plan, on a realistic timeline, not a hopeful one? Compare it against what similar local businesses actually seem to be doing, not what you'd need to be true for the plan to work.

If the honest answer is no, that's exactly the moment to revisit pricing, costs or the whole model — while it's still a spreadsheet, not a business already trading at a loss with a lease that can't be undone.

What to do this week

If you haven't run this number yet, block out thirty minutes before you do anything else on the business plan. List every fixed cost you can think of, including your own pay at a realistic rate, work out the margin on your actual product or service, and divide. Then sense-check the result against your quietest realistic month, not your best one. A rough answer done honestly this week is worth more than a polished business plan that's never actually confronted the number underneath it.

If you're already trading and have never done this calculation, don't skip it just because the launch has already happened — an existing business still benefits from knowing its break-even number, arguably more than a new one, because there's now real sales data to check the assumptions against rather than guesswork. Run the numbers on your actual last twelve months and see how close your busiest and quietest months came to the figure. If your quietest month falls well short of break-even every year without fail, that's not bad luck repeating itself — it's a pricing or cost problem that a calendar reminder won't fix on its own.

Common questions

What is the difference between break-even and cash break-even?

Break-even tells you when you stop making a loss; cash break-even tells you when you stop running out of money, and they arrive at different moments. The standard calculation ignores timing entirely. If your customers pay 30 days after delivery but your suppliers want paying in 14, you can hit your break-even sales volume and still have an empty bank account, because the profit exists on paper before the cash lands. Loan repayments widen the gap further: the interest is a cost in your profit calculation, but the capital repayment is not, and it leaves the account regardless. Work out both numbers — the sales volume that covers costs, and the cash buffer that survives the lag between them.

Should I include my own salary in fixed costs?

Yes, at the rate you would have to pay someone else to do your job. Leaving it out is the single most common way a break-even calculation flatters a plan. A number that only works because the founder takes nothing is not a break-even point at all; it is a deferred loss with your name on it. If you run a limited company you will probably take a modest salary plus dividends, and dividends come out of post-tax profit rather than counting as a cost — so put a realistic market salary in the model even if you do not intend to draw it in year one. If the plan only breaks even when your time is free, that is the finding.

How does VAT change my break-even point?

Once registered you either add 20% to your prices or absorb it out of your margin, and both change the sums. Selling mainly to VAT-registered businesses makes this painless, because they reclaim what you charge. Selling to consumers does not: on the cafe example above, a £4.50 coffee becomes £5.40, or you keep £3.75 instead of £4.50 and your £3 of margin drops to £2.25 — a quarter of it gone, pushing break-even from 1,600 sales a month to 2,134. Registration is compulsory once taxable turnover passes £90,000 in any rolling 12-month period, and you must tell HMRC within 30 days of the end of the month you crossed it. Model the registered version now if you expect to get close.

What if the number comes out looking impossible?

Then you have just saved yourself a lease, which is the entire reason for doing it before launch rather than after. You have four levers, and they are worth working through in order of effect: raise the price, cut the direct cost per sale, cut the fixed costs, or change the model so it needs fewer fixed costs at all. Price is usually the most powerful — on a 40% gross margin, a 10% price rise lifts margin by a quarter and cuts the volume you need by a fifth, whereas a 10% cut in fixed costs only cuts it by a tenth. If none of the four brings the number into what your market could realistically deliver, this version of the plan does not work yet.

Do I need to recalculate this once I am trading?

Yes — at least once a year, and immediately after any change to rent, wages or supplier prices. Break-even is not a launch ritual; it is a number that moves every time a fixed cost moves. A rent review, a new hire, an insurance renewal or a supplier increase you absorbed rather than passed on all push the required sales volume up, usually unnoticed, because no single change looks big enough to bother recalculating for. The useful discipline is to run it on your actual last twelve months rather than a forecast, then hold your quietest month against the answer. If your worst month falls short every single year, that is structural, and working harder in the good months will not fix it.