Break-Even Calculator
Break-even analysis answers one of the most fundamental questions in running a business: how much do I need to sell before I stop losing money? The formula is straightforward — Break-even units = Fixed Costs ÷ (Price per unit − Variable cost per unit). The part in brackets, price minus variable cost, is known as the contribution margin — the amount each unit sold "contributes" toward covering your fixed costs, before any of it becomes profit.
Once you know your break-even point in units, multiplying by your price per unit gives your break-even point in revenue — the total sales figure at which you cover all your costs exactly. Sell below that revenue figure and you're operating at a loss; sell above it and every additional unit contributes directly to profit, since fixed costs are already covered.
Understanding your contribution margin as a percentage (contribution margin ÷ price) is often more useful for comparing different products or pricing scenarios than the raw pound figure, since it tells you what proportion of every pound of revenue is available to cover fixed costs and generate profit, regardless of the specific price point.
Getting an accurate break-even figure depends entirely on correctly separating fixed and variable costs — a mistake here throws off the whole calculation. Fixed costs don't change with sales volume: rent, insurance, most salaries, loan repayments, software subscriptions, and accountancy fees are common examples. You'd pay these whether you sold one unit or a thousand.
Variable costs scale directly with each sale: raw materials, packaging, per-unit delivery or shipping costs, payment processing fees, and sales commissions all fall into this category. Some costs sit awkwardly in between — a warehouse team paid partly on a base salary and partly per order fulfilled, for example — and in these cases it's worth splitting the cost into its fixed and variable components separately rather than forcing it entirely into one category.
It's also worth revisiting this split periodically rather than treating it as fixed forever: a cost that was genuinely fixed at low volume (a single part-time assistant, say) can effectively become variable once you're scaling and need to add staff in proportion to order volume.
Break-even analysis becomes most useful once you move beyond the basic question of "when do I stop losing money" toward active decision-making. Raising your price per unit directly lowers your break-even point in units, since each sale now contributes more toward fixed costs — useful for quickly seeing how sensitive your break-even point is to a price change you're considering.
Adding a target profit figure (rather than just aiming for zero) turns the same formula into a sales target: Fixed Costs plus Target Profit, divided by the contribution margin, tells you exactly how many units you need to sell to hit a specific profit goal — not just survive, but reach a number that actually makes the business worthwhile. This reframing is often more motivating and practically useful for setting sales targets than the raw break-even figure alone, particularly when sharing goals with a sales team or partner.
Imagine a mobile coffee cart with £2,200 a month in fixed costs — pitch fees, insurance, a van lease payment, and a part-time assistant's guaranteed hours. Each coffee sells for £3.50, and the variable cost per cup (beans, milk, cup, lid) works out at £0.90. The contribution margin is therefore £2.60 per cup (£3.50 − £0.90), or about 74% of the selling price.
Dividing £2,200 by £2.60 gives a break-even point of roughly 847 cups a month — about 28 cups a day if trading every day, or closer to 40 a day across a five-day trading week. That's the number needed just to cover costs; not yet a wage for the owner beyond what's already folded into fixed costs.
Now suppose the owner wants £1,500 a month in additional profit on top of covering costs. Adding that to fixed costs (£2,200 + £1,500 = £3,700) and dividing by the same £2.60 contribution margin gives a target of roughly 1,423 cups a month — around 47-48 a day on a five-day week. Seeing this concrete, achievable daily number is often far more useful for day-to-day decision-making than an abstract monthly profit target, because it translates directly into a sales goal the owner can actually track against as the day unfolds.
This example also shows how sensitive break-even is to small pricing changes: raising the price to £3.80 (a 30p increase, less than 9%) lifts the contribution margin to £2.90 per cup, dropping the plain break-even point to around 759 cups a month — nearly 90 fewer cups needed each month to cover the same fixed costs, illustrating why even modest price increases can meaningfully ease the sales pressure on a business with thin margins.
Break-even analysis is a simplified model, and it's worth being aware of what it doesn't capture. It assumes a single product (or a consistent product mix) at a fixed price and fixed variable cost per unit — a business selling several products at different margins needs either a blended average contribution margin or separate break-even calculations per product to get a genuinely accurate picture.
It also assumes fixed costs really are fixed across the entire range of output being considered — in reality, very large increases in volume often require stepping up fixed costs too (a bigger unit, an extra member of staff, a second delivery van), which shifts the whole calculation rather than just moving along the same line. Used as a planning tool for realistic, moderate ranges of sales volume, though, it remains one of the simplest and most genuinely useful pieces of business math available, precisely because it forces a clear-eyed look at costs and pricing that many small business owners otherwise never formalise.