How this calculator works
This calculator finds how many units a product or service needs to sell to cover all costs, using fixed costs, the price charged per unit, and the variable cost of producing each unit. It reports both the exact break-even units and the practical figure rounded up, since you cannot sell a fraction of a unit in most businesses.
The key idea behind the formula is the contribution margin: how much of each unit's price is left over after variable costs to go toward paying off fixed costs. Once enough units are sold to cover fixed costs entirely, every additional unit sold is pure profit (before further cost changes).
The formula
Contribution margin per unit = Price per unit − Variable cost per unitBreak-even units = Fixed costs ÷ Contribution margin per unitBreak-even revenue = Fixed costs ÷ Contribution margin ratio, where Contribution margin ratio = Contribution margin ÷ Price per unitIf price per unit does not exceed variable cost per unit, the contribution margin is zero or negative and no break-even point exists at any sales volume.
Worked example: $10,000 fixed costs, $50 price, $30 variable cost
- Contribution margin = 50 − 30 = $20 per unit.
- Break-even units = 10,000 ÷ 20 = 500 units exactly (already a whole number, so the practical and exact figures match).
- Contribution margin ratio = 20 ÷ 50 = 40%.
- Break-even revenue = 10,000 ÷ 0.40 = $25,000, which also equals 500 units × $50.
Frequently asked questions
Why does the calculator show two different unit figures?
The exact figure (fixed costs divided by contribution margin) is rarely a whole number in practice. The practical figure rounds up to the next whole unit, since selling a fractional unit is not possible and rounding down would leave the business short of covering fixed costs.
What counts as a fixed cost versus a variable cost?
Fixed costs stay the same regardless of how many units you sell, such as rent, salaries, and insurance. Variable costs scale with each unit sold, such as raw materials, packaging, and per-unit shipping or labor.
What if my price is lower than my variable cost?
Then each unit sold loses money before fixed costs are even considered, and no volume of sales can reach break-even. The calculator flags this case directly instead of showing a meaningless negative or infinite unit count.
How is this different from a margin or markup calculation?
Margin and markup describe profitability on a single unit's price and cost. Break-even analysis uses that same per-unit contribution margin but adds fixed costs to answer a different question: how many units in total are needed before the business stops losing money.
How can I lower my break-even point?
Since break-even units equal fixed costs divided by the contribution margin per unit, you can lower the break-even point by cutting fixed costs, raising the price per unit, or reducing the variable cost per unit — each change either shrinks the numerator or grows the denominator in that formula. For example, with $10,000 in fixed costs, a $30 variable cost per unit and a $50 price giving a $20 contribution margin, raising the price would increase that margin and lower the number of units needed to reach break-even without cutting any costs at all.