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How to Calculate a Break-Even Point
Break-even tells you how much you have to sell before you stop losing money. The formula is short; getting fixed and variable costs on the right side of the line is the real work.
Break-even is the sales volume at which total revenue equals total costs. Below it you are losing money, above it you are making it. To find it you need three numbers: your fixed costs, your selling price per unit, and your variable cost per unit.
The formulas
Contribution margin is the part of each sale left over after the costs of making that sale. It is what 'contributes' to covering the fixed costs. Once the fixed costs are fully covered, every further unit's contribution margin becomes profit.
Contribution margin per unit = Price per unit - Variable cost per unit Break-even in units = Fixed costs / Contribution margin per unit Break-even in revenue = Fixed costs / (Contribution margin per unit / Price per unit)
Separating fixed from variable costs
Fixed costs do not change with how much you sell in the period: rent, insurance, salaried staff, software subscriptions, accounting fees, equipment leases. You pay them whether you sell one unit or a thousand.
Variable costs move directly with each sale: materials, packaging, payment processing fees, shipping, per-unit manufacturing, commission.
Some costs are genuinely mixed. A phone plan with a monthly fee plus per-minute charges is part fixed, part variable, and should be split. Utilities in a workshop behave the same way — a base load that exists regardless, plus consumption that rises with production.
The common error is classifying a cost by how it feels rather than by how it behaves. A part-time employee on fixed hours is a fixed cost even though the role feels flexible. A contractor paid per job is variable even though you may use them every month.
Worked example
A small business sells a product for 45. Materials, packaging and payment fees come to 18 per unit. Monthly fixed costs are rent 900, software 120, insurance 60 and a part-time wage 1,320, totalling 2,400.
Contribution margin is 45 - 18 = 27 per unit.
Break-even in units is 2,400 / 27 = 88.9, so 89 units a month. Always round up: 88 units leaves you fractionally short.
Break-even in revenue is 89 x 45 = 4,005, or calculated directly, 2,400 / (27/45) = 2,400 / 0.60 = 4,000.
The useful follow-up question is what happens either side of that. At 120 units, profit is (120 x 27) - 2,400 = 840. At 60 units, the loss is (60 x 27) - 2,400 = -780.
Testing changes before you make them
The table shows why price changes move break-even so sharply. A 5 price rise on a 45 product is an 11% increase in price but an 18.5% increase in contribution margin, because the margin is the smaller number. The same logic runs the other way and is the reason a modest discount can require a surprisingly large increase in volume just to stand still.
| Change | New break-even (units) | Effect |
|---|---|---|
| Baseline | 89 | Margin 27 per unit |
| Raise price to 50 | 65 | Margin rises to 32; fewer units needed |
| Cut material cost to 15 | 80 | Margin rises to 30 |
| Add 500 fixed costs | 108 | Fixed costs up to 2,900 |
| Discount price to 40 | 110 | Margin falls to 22 |
Break-even for services and freelancing
The same structure works when you sell time instead of units, with billable hours as the unit. Fixed costs become your monthly overheads plus the income you need to draw. Variable costs per hour are usually small — software allocated per project, subcontracted work, transaction fees.
Where this gets misread is utilisation. If your overheads and required income total 4,000 a month and you net 60 per billable hour after variable costs, break-even is roughly 67 billable hours. That is not 67 hours of work; it is 67 hours a client pays for. Once admin, quoting, invoicing and unbillable time are included, that can easily mean a 100-hour month.
Assumptions that quietly break a break-even estimate
- Leaving your own salary out of fixed costs. If you need to draw an income, it belongs in the calculation, otherwise break-even is really break-even-while-working-unpaid.
- Treating a cost as fixed because it is paid monthly. Payment schedule and cost behaviour are different things.
- Calculating break-even across a mixed product range using an average margin, when the sales mix can shift.
- Ignoring tax and payment processing fees, which quietly reduce contribution margin on every sale.
- Rounding the unit answer down. Partial units do not cover costs.
Assumptions and limitations
The formula assumes price and variable cost per unit stay constant across every unit sold. In reality, bulk discounts reduce material costs at volume and larger orders may attract lower prices, so the real break-even curve bends where a flat calculation shows a straight line.
It assumes fixed costs are genuinely fixed within the range you are considering. They usually are, until a threshold — a second machine, a larger unit, another hire — at which point they step up and break-even jumps with them. Recalculate at each step rather than extrapolating.
It also assumes you can sell what you produce. Break-even tells you the volume required, not whether that volume is achievable in your market. A calculation showing you need 89 units a month is only useful alongside an honest view of whether 89 units a month is realistic, and a business that breaks even at close to its maximum capacity has no room to absorb a bad quarter.
Run a sensitivity check around break-even
Break-even is a point estimate built from assumptions about fixed costs, variable cost per unit and selling price. Change any of those inputs and the point moves. A practical check is to calculate the result again with a modestly lower selling price or higher variable cost. If the required sales volume changes sharply, the business is more sensitive to pricing or cost changes than the single break-even number suggests.
Frequently asked questions
Should tax be included in break-even?
Taxes charged on sales, such as VAT or sales tax, are excluded from both price and revenue since they pass through. Taxes on profit sit above break-even by definition, because at break-even there is no profit to tax.
How do I calculate break-even with several products?
Use a weighted average contribution margin based on your expected sales mix, and recalculate when the mix changes. If the products differ a lot, break-even per product line is more informative.
What is the margin of safety?
The gap between your actual sales and your break-even point, usually expressed as a percentage of sales. It shows how far revenue could fall before you start losing money.
Does break-even account for cash flow timing?
No. It is a profitability measure. A business can be above break-even on paper and still run out of cash if customers pay late, which is why break-even and a cash flow forecast are both needed.
Can break-even sales be negative?
Not in a conventional unit-sales model. A negative or nonsensical result usually signals an input or formula problem, such as contribution margin being zero or negative.
Does break-even tell me how much profit I will make?
No. It identifies the point where modeled revenue equals modeled costs. Profit begins above that point only under the assumptions used.
Conclusion
Break-even comes down to one division, but it is only as good as the cost classification underneath it. Split fixed from variable by how each cost behaves rather than how it is billed, include your own income in fixed costs, and round the unit answer up. Then use it the way it is most valuable: not as a single target, but as a way to test what a price change, a new overhead or a discount would actually require you to sell.
Figures in this article are illustrative. Results depend on your own rates, fees, taxes and circumstances, and are for educational and planning purposes rather than financial advice.