How the sales break-even calculator works
Sales break-even analysis asks how many comparable deals must close before their combined contribution covers fixed costs. Contribution is the amount left from each sale after variable costs. Dividing fixed costs by that amount produces a theoretical sales count; rounding up gives the whole deals required to reach or pass break-even.
The revenue output uses the rounded whole-deal count. It can therefore be slightly above the continuous mathematical break-even point. This is intentional: when a business sells complete contracts rather than fractional units, the next full sale is what covers the remaining cost.
Contribution per sale = price − variable cost; break-even sales = ceiling(fixed costs ÷ contribution per sale)
Worked example
Start with the example inputs below. The calculator opens with these values; reset the example at any time to compare your own scenario. Monetary examples use GBP, and all amounts must use the same currency.
| Measure | Value |
|---|---|
| Fixed costs for the period | 20000 |
| Revenue per sale | 5000 |
| Variable cost per sale | 2000 |
| Measure | Value |
|---|---|
| Whole sales needed to break even | 7 |
| Revenue at whole-sale break-even | £35,000.00 |
| Contribution per sale | £3,000.00 |
Fixed costs and sales must use the same period. Variable cost should include delivery costs and per-sale commissions.
How to use the result
Use one period for every input. Monthly fixed costs need revenue and variable costs attributable to the same monthly sales model. Include per-sale commissions and delivery work in variable cost, but avoid counting those amounts again under fixed costs.
If your sales mix varies substantially, run separate scenarios or use a justified weighted average contribution. The number of low-margin deals needed can differ greatly from the number of high-margin deals needed, even when their selling prices are similar.
Assumptions and common mistakes
Break-even requires positive contribution. When selling price does not exceed variable cost, additional sales cannot cover fixed costs in this model. The calculation excludes working capital, collection timing, finance costs and taxes. It is a scenario tool, not a complete financial forecast.