Every business owner has felt it: you’re generating revenue, paying your bills, watching money flow in and out — but you’re not sure whether you’re actually profitable yet, or how much you need to sell before you are. Break-even analysis answers that question with precision. It tells you the exact point at which your revenue covers all your costs, leaving neither a profit nor a loss. Below that point, every sale contributes to covering your overheads. Above it, you’re making money. Understanding where that line sits is one of the most useful things any SME owner can know about their business.
What Is Break-Even Analysis?
Break-even analysis is the process of calculating the sales volume — in units or in revenue — at which a business’s total income exactly equals its total costs. At the break-even point, profit is zero: you are covering everything you spend, but not yet generating surplus.
The concept underpins a huge range of financial decisions: setting selling prices, evaluating the viability of a new product line, planning how many units to produce, assessing the impact of taking on a new lease, or deciding whether a marketing campaign will pay for itself. It is a core tool in management accounting precisely because it converts cost data into an actionable threshold — a target to hit before profitability begins.
Break-even analysis is built on one foundational distinction: the difference between fixed costs and variable costs.
Fixed Costs vs. Variable Costs: Why the Difference Matters
To run a break-even calculation, you need to split your costs into two categories.
Fixed costs are expenses that remain constant regardless of how much you produce or sell. Rent, insurance premiums, salaried staff, software subscriptions and loan repayments are fixed costs. Whether you sell 10 units or 10,000 units this month, your rent stays the same. These costs exist simply because you are operating.
Variable costs are expenses that rise or fall in direct proportion to your output. Raw materials, packaging, sales commissions, delivery costs and hourly labour are typically variable. If you sell twice as many products, your variable costs roughly double.
The practical importance of this split is that it isolates what each additional unit of sale actually costs you to produce — and how much of the selling price is available to cover your fixed overheads. That available amount is called the contribution margin.
Key insight: The contribution margin is the portion of each sale that “contributes” to covering your fixed costs. Once fixed costs are fully covered, every additional pound of contribution margin becomes profit.
The formula is straightforward:
Contribution Margin = Selling Price per Unit − Variable Cost per Unit
If you sell a product for £50 and it costs you £20 in variable costs to produce and ship each unit, your contribution margin per unit is £30.
Calculating Your Break-Even Point
Once you know your fixed costs and contribution margin, the break-even formula is simple:
Break-Even Point (in units) = Total Fixed Costs ÷ Contribution Margin per Unit
You can also express this as a revenue figure:
Break-Even Point (in revenue) = Total Fixed Costs ÷ Contribution Margin Ratio
Where: Contribution Margin Ratio = Contribution Margin per Unit ÷ Selling Price per Unit
These two formulas give you the same answer expressed in different units — which is useful depending on whether you think in terms of items sold or money collected.
Worked Example: Orchard & Co.
Suppose Orchard & Co. is a small business selling handmade ceramic mugs online. Here is their cost structure:
| Item | Monthly Amount | Cost Type |
|---|---|---|
| Studio rent | £1,200 | Fixed |
| Owner salary (fixed draw) | £1,800 | Fixed |
| Website subscription & insurance | £200 | Fixed |
| Total Fixed Costs | £3,200 | |
| Clay and glazes per mug | £8 | Variable |
| Packaging & shipping per mug | £7 | Variable |
| Total Variable Cost per Unit | £15 | |
| Selling price per mug | £45 | |
| Contribution Margin per Unit | £30 |
Applying the formula:
Break-Even Point = £3,200 ÷ £30 = 107 mugs per month
Orchard & Co. needs to sell 107 mugs every month before they make a single pound of profit. Expressed as revenue:
Contribution Margin Ratio = £30 ÷ £45 = 66.7%
Break-Even Revenue = £3,200 ÷ 0.667 = £4,798 per month
In other words, the business needs to generate just under £4,800 in monthly sales to break even. Sale 108 onwards is pure profit at a margin of £30 each.
How to Use Break-Even Analysis in Practice
The real value of break-even analysis is not the number itself — it is what you do with it.
Pricing decisions. If your current selling price produces a contribution margin so thin that the break-even point is unrealistic (say, 3,000 units a month when you typically sell 400), your price is too low or your variable costs are too high. Break-even analysis makes this structural problem visible immediately.
Evaluating new costs. Considering hiring a part-time member of staff at £800 a month? That increases your fixed costs and raises your break-even point. You can calculate exactly how many additional units you need to sell to justify the hire before committing.
Stress-testing scenarios. If your supplier raises material costs, how does that affect your contribution margin and break-even volume? If you discount your price for a sale campaign, does the increased volume required to compensate make commercial sense? Break-even analysis lets you model these scenarios quickly.
Assessing product viability. For a new product line, build a break-even model before launch. If the numbers require an implausible sales volume to cover development and marketing costs, it may not be the right moment to proceed.
For businesses operating across multiple entities or product lines, understanding break-even at both the entity and group level adds another layer of insight. BrizoConsol’s guide on group KPI reporting for multi-entity businesses explores how finance teams track profitability and performance metrics consistently across different parts of the group.
Limitations of Break-Even Analysis
Break-even analysis is powerful, but it rests on a set of assumptions that do not always hold in the real world. Understanding these limitations helps you use the tool intelligently rather than treating its output as certainty.
First, the model assumes that all fixed costs remain truly fixed and that variable costs scale perfectly linearly with output. In practice, step-costs exist: hiring a second member of staff, for example, creates a jump in fixed costs once volume reaches a certain point — this is not captured in a simple break-even model.
Second, the analysis typically treats your product mix as constant. If you sell multiple products with different contribution margins, your overall break-even depends on which products you sell and in what proportions — a concept known as the weighted-average contribution margin. A business that suddenly sells proportionally more low-margin products will find its break-even point rises even if total revenue holds steady.
Third, break-even analysis looks only at costs and revenue — it does not account for cash timing. A business can be above its break-even point on paper and still face cash flow shortfalls if customers pay 60 days late. Always pair break-even analysis with a cash flow view. You can explore this further in our guide to cash flow forecasting for SMEs.
Finally, break-even analysis is a snapshot. As your cost structure evolves — rent reviews, wage increases, changes in supplier pricing — the model needs updating. Build it into your regular financial review cycle, not just as a one-off exercise at launch.
Key Takeaways
- Break-even analysis identifies the exact sales volume at which total revenue equals total costs — profit is zero at this point; every additional unit sold beyond it generates profit.
- Fixed costs stay constant regardless of output (rent, salaries, insurance); variable costs rise with production (materials, packaging, commissions).
- Contribution margin = selling price minus variable cost per unit. This is the portion of each sale available to cover fixed costs.
- Break-Even Point (units) = Total Fixed Costs ÷ Contribution Margin per Unit.
- Break-even analysis is most useful for pricing decisions, evaluating new costs, stress-testing scenarios, and assessing the viability of new products or services.
- The model has limitations: it assumes fixed cost stability, linear variable costs, and a constant product mix — supplement it with cash flow analysis and a multi-product contribution margin view where relevant.
- Revisit your break-even model whenever your cost structure changes materially.
Related Reading
Break-even analysis is most useful when paired with a broader understanding of your financial statements and cost structure. These ARD guides cover the essential context:
- Understanding the Income Statement: A Complete Guide to Profit & Loss for SMEs — where the revenue and cost figures used in break-even analysis come from.
- Cost of Goods Sold (COGS) Explained — understanding the variable cost components that drive your contribution margin.
- Financial Ratios Explained: Liquidity, Profitability, and Efficiency Ratios — how to extend your financial analysis beyond break-even to measure ongoing performance.
- Budgeting and Forecasting for SMEs — embedding your break-even model into an annual financial plan.