Before a new product, service line, or side business turns a profit, it has to clear a specific number of sales first — not zero, and not some vague "eventually." This calculator turns your fixed costs, price per unit, and variable cost per unit into that exact number: how many units you need to sell before the business stops losing money, plus the revenue that break-even point represents.
How it works
Every unit you sell brings in its price, but a slice of that price goes straight to variable cost — materials, packaging, a payment processing fee, whatever scales with volume. What is left over after variable cost is the contribution margin: the amount each sale actually contributes toward paying off your fixed costs, the expenses that show up whether you sell one unit or a thousand.
Divide your fixed costs by that per-unit contribution margin and you get the number of units it takes to fully offset fixed costs — the break-even point. Because you cannot sell a fraction of a unit and call the business break-even, that number always rounds up to the next whole unit: selling 249.6 units still leaves you short, so it takes the 250th sale to actually clear the line. Multiply the rounded unit count by price per unit and you get break-even revenue — the total sales figure that same point represents.
If price per unit does not exceed variable cost per unit, contribution margin is zero or negative, and no number of sales will ever reach break-even — each unit sold loses money rather than clawing back fixed costs. The calculator flags that case instead of returning a meaningless answer.
Worked example
A small workshop has $5,000 in monthly fixed costs, sells its product for $50 per unit, and pays $30 per unit in materials and packaging.
- Contribution margin: $50 − $30 = $20 per unit
- Break-even units: $5,000 ÷ $20 = 250 exactly, rounds up to 250 units
- Break-even revenue: 250 × $50 = $12,500
Sell fewer than 250 units in the month and fixed costs are not fully covered; sell 250 or more and every additional unit sold is pure contribution toward profit, since fixed costs no longer need covering.
How to interpret your result
Break-even units is the floor, not a sales target — it's the point where profit turns from negative to zero, not the point where the business is actually working. Anything sold beyond that number carries only variable cost, so contribution margin on every unit past break-even flows straight to profit, which is why the units right after break-even are disproportionately valuable compared to the units that got you there.
Break-even revenue is useful as a sanity check against your actual sales capacity: if that revenue figure is far beyond what your market, ad budget, or sales pipeline can realistically produce in your planning window, the fixed-cost, price, or variable-cost inputs need to change before the plan is workable — not the arithmetic. Three levers move the break-even point: raising price per unit, cutting variable cost per unit, or cutting fixed costs. The first two shrink the number of units you need to sell; the third shrinks the number directly without touching volume at all, which is often the fastest fix if fixed costs have crept up.
This is a single-product estimate. A business selling multiple products at different margins needs a blended or weighted-average contribution margin to get an accurate break-even figure — running each product line through this calculator separately, then combining the results, is more honest than averaging inputs upfront.
Methodology & sources
The formulas: contributionMargin = pricePerUnit − variableCostPerUnit, breakEvenUnits = ceil(fixedCosts ÷ contributionMargin), breakEvenRevenue = round(breakEvenUnits × pricePerUnit). If contribution margin is zero or negative, no break-even point exists and the calculator raises an error instead of returning a number.
This is the standard break-even analysis used across small-business planning — fixed costs divided by contribution margin per unit — the same core calculation the U.S. Small Business Administration points founders toward when budgeting startup costs and planning for profitability. It assumes a single product or service at a constant price and constant variable cost per unit; it does not model bulk-pricing discounts, seasonal cost swings, or a shifting sales mix, so treat the result as a planning benchmark to revisit as your actual costs and pricing settle in.