How break-even calculator works
The break-even point is the sales volume at which total revenue exactly equals total costs, so profit is zero. Below it you run at a loss; every unit sold above it contributes pure profit. It is the single most useful number for deciding whether a price, a product launch or a service rate is viable.
The engine is the contribution margin per unit: the portion of each sale left after the variable cost of making that unit. It is calculated as price per unit minus variable cost per unit. Divide your fixed costs by that margin and you get the break-even units; multiply by the price and you get the break-even revenue.
Enter your fixed costs (rent, salaries, software - anything that does not change with volume), your price per unit, and your variable cost per unit (materials, payment fees, per-unit shipping). The tool shows the exact break-even units, the whole units you need to sell (rounded up, since you cannot sell a fraction), the break-even revenue, and the contribution-margin ratio as a share of price.