The Number Everyone Quotes and Almost Nobody Checks
Ask a business owner what their break-even is and you will usually get one of two answers. Either a confident number they worked out once, in a spreadsheet, in the year they started trading, or a slightly embarrassed shrug.
Both answers point at the same problem. Break-even is treated as a fact about the business, something you establish and then know. It is not. It is the output of a calculation with four moving inputs, and at least two of those inputs change every quarter without anyone noticing. A break-even figure from eighteen months ago is not a stale number. It is a wrong one.
This guide covers the mechanics properly: what break-even means, how to calculate it in units and in revenue, what contribution actually is, how to read a break-even chart and why the one in the textbook is drawn wrong. Then it covers the part that gets left out, which is the gap between the break-even your accounts show and the sales you genuinely need to keep the business, the loans and yourself going. In our experience that gap is usually somewhere between thirty and forty percent, and it is the single most common reason a technically profitable small company feels permanently broke.
What Break-Even Actually Means
Your break-even point is the level of sales at which total revenue exactly equals total costs. Above it you make a profit. Below it you make a loss. At it, precisely, you have worked a year for nothing.
The idea only works because costs behave in two different ways. Some costs move with sales and some do not. If every cost rose in step with revenue there would be no break-even point, because you would make the same proportional margin on the first pound as on the millionth. It is the presence of costs that stay put regardless of trade, the fixed costs, that creates a level of sales you have to clear before anything is yours.
So break-even analysis is really an exercise in sorting. Every cost in the business gets pushed into one of two piles:
- Variable costs rise and fall with the volume you sell. Materials, stock, subcontract labour, card processing fees, delivery to the customer. Sell nothing and you spend nothing on them.
- Fixed costs arrive whether you trade or not. Rent, business rates, salaried staff, insurance, software subscriptions, accountancy fees. These are your overheads, and they are the reason break-even exists as a concept.
The sorting is the hard part, not the arithmetic. Most costs are obvious, a few are genuinely arguable, and where you put the arguable ones changes your answer. We come back to that below, because in service businesses it changes the answer enormously.
Contribution: The Engine of the Formula
Before the formula there is one idea to get straight, and it is the one people skip.
Contribution is what is left from a sale after the variable costs of making that sale. It is not profit. It is the amount each sale contributes towards covering the fixed costs, and once the fixed costs are covered, everything after that is profit.
There are two ways to express it and you need both.
Contribution per unit = selling price − variable cost per unit
Contribution margin ratio = contribution ÷ selling price
Take a coffee roastery selling retail boxes at £24. Beans, packaging, card fees and carriage out come to £14.40 a box. Contribution per unit is £9.60, and the contribution margin ratio is £9.60 ÷ £24, which is 40 percent. Forty pence in every pound of sales is available to pay the rent.
Contribution is not the same as gross profit, although the two often land in a similar place. Gross profit is a statutory presentation, revenue less cost of sales, and cost of sales may well include costs that do not vary with volume, such as factory rent or a salaried production manager. Contribution is a management concept and it draws the line strictly at variable. If your accounts put a supervisor's salary in cost of sales, your gross margin and your contribution margin will differ, and the contribution figure is the one to use for break-even.
The Break-Even Formula
There are two versions and they answer different questions.
Break-even point in units = fixed costs ÷ contribution per unit
Break-even point in revenue = fixed costs ÷ contribution margin ratio
Back to the roastery. Its annual fixed costs are £120,000: £34,000 of rent and rates, £62,000 of salaries, and £24,000 of insurance, utilities, software and professional fees.
- Break-even in units: £120,000 ÷ £9.60 = 12,500 boxes
- Break-even in revenue: £120,000 ÷ 0.40 = £300,000
Same answer, two currencies. 12,500 boxes at £24 is £300,000, so the two versions agree, as they always will.
The units version is the one to use if you sell one thing, or a small number of similar things, because it converts directly into an operational target: 12,500 boxes is 240 a week, which is something a production manager can act on. The revenue version is the one to use for a mixed business, because you cannot add boxes to consultancy days. Almost every real business needs the revenue version, and almost every explanation you will read online teaches the units version, which is part of why break-even has a reputation for being an exam topic rather than a management tool.
The Break-Even Chart, and Why the Textbook Version Is Misleading
The classic break-even chart puts sales volume along the bottom and money up the side, then draws three lines. A flat horizontal line for fixed costs. A total cost line starting at the fixed cost level and sloping upward as variable costs accumulate. A revenue line starting at zero and climbing more steeply. Where the revenue line crosses the total cost line is the break-even point. The wedge to the left is the loss, the wedge to the right is the profit.
It is a good picture and it makes the concept obvious in a way the formula does not. It is also wrong in a specific way that matters.
Fixed costs are not a horizontal line. They are a staircase. Fixed costs are only fixed within a range of activity. Sell more and eventually you need a second van, another unit, another full-time person, a bigger machine. At that moment the horizontal line jumps vertically, and your break-even point jumps with it.
The roastery is at 15,000 boxes a year, £360,000 of revenue, making £24,000 of profit. Contribution is 15,000 × £9.60, which is £144,000, less fixed costs of £120,000. Comfortable enough. But 15,000 boxes is roughly the capacity of one roaster and the current team. Growing past it means a second roaster and another full-time person: £34,000 of salary and £12,000 of finance and space, so fixed costs go to £166,000.
Watch what happens the day that commitment is signed:
| Before expansion | After expansion | |
|---|---|---|
| Fixed costs | £120,000 | £166,000 |
| Break-even revenue | £300,000 | £415,000 |
| Profit at current £360,000 of sales | £24,000 | −£22,000 |
| Sales needed to earn the old £24,000 | £360,000 | £475,000 |
A business that was profitable is now loss-making at exactly the same level of trade, and it needs to grow sales by nearly a third to get back to the profit it was already making. This is the second break-even point, and it is the reason so many small businesses have a bad year immediately after a good one. Nothing went wrong. They simply crossed a step and spent the following eighteen months in the trough underneath it.
Our view, and it is a strong one, is that the incremental break-even is more useful than the whole-business break-even. Before you sign a lease or make a hire, the question is not "what is my break-even" but "how much extra sales does this specific commitment need to generate to pay for itself, and how long will that realistically take". For the roastery, the second person needs £115,000 of extra annual sales at a 40 percent contribution just to be neutral. If the honest answer is that the new capacity will not deliver that for two years, the decision is still fine, but it now needs to be funded as an investment rather than absorbed as an overhead.
Margin of Safety: The Number Worth Watching Monthly
Break-even on its own tells you where the floor is. It does not tell you how far above it you are standing, which is the thing you actually want to know.
Margin of safety = (current sales − break-even sales) ÷ current sales
For the roastery before it expands, that is (£360,000 − £300,000) ÷ £360,000, which is 16.7 percent. Sales can drop by a sixth before the business stops making money.
A percentage is fine, but it is easier to act on when converted into time. Sixteen point seven percent of a 52 week year is just under nine weeks. That is a more honest way to hold the number: this business can lose a little under nine weeks of trading before it is working for nothing. Told that way, an owner tends to have a view about whether that is enough, and about whether a quiet January and a slow August together might use it up. Told as a percentage, it usually gets nodded at and forgotten.
Margin of safety is also the right number to put in monthly management accounts, because it moves. Break-even changes when costs change, which is a few times a year. Margin of safety changes every month, because sales change every month, and it compresses two facts into one figure the owner can read in a second.
Your Real Break-Even Is Higher Than Your Accounts Say
Here is the part that break-even guides tend to leave out, and it is the part that matters most to an owner-managed company.
Break-even as normally calculated is an accounting concept. It tells you the sales at which your profit and loss account shows zero. But three significant cash obligations of a small limited company do not appear in the profit and loss account at all, and one significant cost in the profit and loss account never leaves the bank.
- Depreciation is a fixed cost that costs no cash. It is an accounting spread of an asset you already paid for. For break-even measured in cash terms, take it out.
- Loan and finance capital repayments are cash that never touches the profit and loss account. Only the interest is a cost. The capital element of every asset finance payment, bounce back loan repayment or director's loan repayment is pure cash out with no effect on reported profit.
- Corporation tax is a cash cost you cannot avoid. At 19 percent on profits up to £50,000, and an effective 26.5 percent on profits inside the marginal band between £50,000 and £250,000, it needs to be funded out of the same contribution.
- Dividends are not a cost. This is the big one. Most owner-managers take a small salary plus dividends. The salary sits in fixed costs, so break-even accounts for it. The dividends do not, because a dividend is a distribution of post-tax profit, not an expense. So your break-even is calculated for a version of the business in which you personally live on the salary alone.
Put those together for the roastery. Say £9,600 of its £120,000 fixed cost base is depreciation, it repays £18,000 a year of capital on the roaster and van finance, and the director takes a £12,570 salary, which is already inside fixed costs, plus £30,000 of dividends to live on.
| Break-even measured as | Sales required |
|---|---|
| Cash costs only, ignoring the owner and the loans | £276,000 |
| Accounting break-even, the standard formula | £300,000 |
| Everything the business actually has to fund | about £418,500 |
The third figure is the one that governs whether the bank balance grows or shrinks, and it is 39 percent above the number the standard formula gives. At its current £360,000 of sales this business reports a £24,000 profit, files perfectly healthy accounts, and still cannot pay the director what they need without the overdraft doing the work. Nothing is wrong with the bookkeeping. The owner is simply measuring against the wrong line.
We would go further and say the accounting break-even is close to useless for a small company as a survival measure. Calculate it, by all means, because it is the basis for everything else. But the number to write on the wall is the third one: fixed costs, less depreciation, plus capital repayments, plus the tax on the profit required, plus what the owner needs to take out. If you only ever work out one break-even figure, work out that one. It also explains a pattern we see constantly, which is a business that is profitable on paper and short of working capital in reality.
Break-Even for Service Businesses: Count Hours, Not Units
If you sell time rather than things, the standard formula quietly falls apart.
The reason is that your largest cost, the salaries of the people delivering the work, is fixed in the short term. A salaried consultant costs the same in a slow month as a busy one. So if you sort costs honestly, almost everything is fixed and your variable costs are close to zero, which means your contribution margin ratio is close to 100 percent and your break-even revenue is simply "cover the overheads". Technically correct, operationally useless, because it gives you no idea what the team has to do.
The version that works is a capacity break-even. Instead of asking how much revenue you need, ask how many billable hours you need, and then what proportion of your available hours that is.
Break-even hours = fixed costs ÷ charge-out rate
Break-even utilisation = break-even hours ÷ available hours
An agency with three delivery staff, a charge-out rate of £75 an hour, and total fixed costs of £240,000 including all salaries, needs £240,000 ÷ £75, which is 3,200 billable hours. If each person realistically has 1,600 chargeable-capable hours a year after holiday, sickness, training and admin, capacity is 4,800 hours, so break-even utilisation is 3,200 ÷ 4,800, or 66.7 percent.
That number is worth more than any revenue target, because it is the difference between:
| Utilisation | Billable hours | Fee income | Profit |
|---|---|---|---|
| 60 percent | 2,880 | £216,000 | −£24,000 |
| 66.7 percent | 3,200 | £240,000 | £0 |
| 70 percent | 3,360 | £252,000 | £12,000 |
| 75 percent | 3,600 | £270,000 | £30,000 |
Ten points of utilisation is the entire difference between a £24,000 loss and a £30,000 profit, on the same team, in the same office, at the same rate. Very few agencies and consultancies we meet know their break-even utilisation, and almost none of them tell their delivery team what it is. It is hard to think of a single number that would change behaviour more.
The Sales Mix Problem, or Why Your Break-Even Expires
The revenue formula has an assumption buried in it that nobody states out loud. Fixed costs ÷ contribution margin ratio only works if the contribution margin ratio holds, and that ratio is an average across whatever you happened to be selling when you calculated it.
The roastery does not only sell retail boxes. It sells retail at a 46 percent contribution and wholesale sacks at 22 percent, and it currently runs at roughly three quarters retail. Blend those and you get the 40 percent ratio used above, which produced a £300,000 break-even.
Now suppose wholesale grows, as wholesale tends to, because the orders are larger and the sales effort per pound is lower. The mix drifts to fifty-fifty. Nothing else changes. No cost rises, no price falls, nobody does anything wrong.
The blended contribution ratio falls to 34 percent. Break-even revenue becomes £120,000 ÷ 0.34, which is £352,900. The break-even point rose by nearly £53,000 without a single cost changing. And at the same £360,000 of sales the business now makes about £2,400 instead of £24,000.
This is why we treat break-even as a number with an expiry date attached. It is not a property of the business, it is a property of the business selling a particular basket of things. Growth in the wrong part of the mix will move the floor up underneath you while the top line is going in the direction everybody wanted, and the profit and loss account only tells you afterwards. If you sell more than one thing at materially different margins, recalculate whenever the mix shifts by ten points or more, and track contribution by product line rather than only in total.
The VAT Threshold Moves Your Break-Even Overnight
There is one UK-specific event that raises break-even more abruptly than anything else, and it catches consumer-facing businesses every year.
The VAT registration threshold is £90,000 of taxable turnover on a rolling twelve-month basis, and it has been frozen at that level since 1 April 2024. If you sell to other VAT-registered businesses, crossing it is largely administrative, because your customers reclaim the VAT and are indifferent. If you sell to consumers, it is not administrative at all. Consumers cannot reclaim anything, so either your prices rise by 20 percent, or one sixth of every sale stops being yours.
Take a hair salon. A cut is £45, the products, laundry and card fees come to £8, so contribution is £37. Fixed costs, being rent, salaries and utilities, are £74,000. Break-even is £74,000 ÷ £37, which is 2,000 cuts a year. At £45 a cut, that is £90,000 of sales, which is precisely the VAT threshold.
Cross it and hold prices, because the salon next door has not crossed it. Now £45 becomes £37.50 of revenue and £7.50 for HMRC. The £8 of variable cost becomes £6.67, since the input VAT is now recoverable. Contribution per cut falls from £37 to £30.83.
New break-even: £74,000 ÷ £30.83 = 2,400 cuts, or £108,000 of gross sales.
Four hundred extra haircuts a year, eight a week, purely to stand still. No cost went up, no price came down, no customer left. There is a genuine dead zone above the threshold in which a consumer-facing business is worse off than it was underneath it, and it does not escape until it is roughly 20 percent bigger. This is worth modelling before you get near the line rather than after, because the options, which are raising prices, deliberately managing turnover below the threshold, restructuring, or accepting the hit and growing through it, all need lead time. It is one of the more consequential tax planning conversations a small business has, and it is far easier to have it at £78,000 of turnover than at £94,000.
Common Break-Even Mistakes
- Using gross profit instead of contribution. If cost of sales contains anything that does not vary with volume, your contribution ratio is understated and your break-even is too high.
- Calculating it once. Costs change, prices change, mix changes. An annual recalculation is a minimum, and after any significant hire or lease it should be immediate.
- Drawing fixed costs as a flat line. They are steps. Know where your next step is and what it costs before you reach it.
- Ignoring capital repayments. Loan capital does not appear in your profit and loss account and does not reduce your reported profit, but it empties the bank all the same.
- Forgetting the owner needs paying. Dividends are not an expense, so the standard formula assumes an owner who lives on nothing.
- Applying a single blended ratio to a business with very different margins. Averages hide the thing you need to see.
- Treating break-even as a target. It is a floor, not a goal. A business trading at break-even is generating no return on the capital in it, and no reward for the risk of running it.
- Leaving VAT out of the model when the threshold is within reach and the customers are consumers.
How IAK Can Help
Break-even is one of those calculations that is trivial once the underlying numbers are right, and impossible when they are not. Nearly every break-even conversation we have starts as a bookkeeping job: separating genuinely variable costs from overheads that have been coded alongside them, splitting revenue by product or service line so a blended margin means something, and getting the chart of accounts into a shape where the answer falls out each month instead of being reconstructed once a year.
From there we build it into monthly management reporting: break-even revenue, contribution by line, margin of safety expressed in weeks, and for service businesses the break-even utilisation rate. We also model the version that includes your drawings, your loan repayments and your tax, because that is the number that decides whether the year works for you personally rather than only on paper.
If you are approaching the VAT threshold, weighing up a hire or a bigger unit, or you simply cannot square a profitable set of accounts with a bank balance that never moves, get in touch. We work with retailers, trades, agencies and professional firms across North London, and this is usually a one-afternoon problem that has been costing money for years.
Sources
- Register for VAT, GOV.UK, for the £90,000 taxable turnover registration threshold and the rolling twelve-month backward look.
- Corporation Tax rates, GOV.UK, for the 19 percent small profits rate, the 25 percent main rate and the £50,000 and £250,000 thresholds used in the funding break-even example.
- Work out your Marginal Relief for Corporation Tax, GOV.UK, for the tapered rate between the two thresholds that produces the 26.5 percent effective marginal cost.