THE NUMORIX GUIDE
How to use the Breakeven Calculator
Last reviewed September 14, 2026
What this calculator does
The route subtracts variable cost per unit from selling price per unit to find contribution margin per unit.
Formula and method
The route subtracts variable cost per unit from selling price per unit to find contribution margin per unit. Break-even units are the ceiling of fixed costs divided by that margin, and break-even revenue is units multiplied by selling price. Contribution-margin ratio is margin per unit divided by selling price.
Variables and inputs
Enter fixed costs, variable cost per unit, and selling price per unit. All inputs are currency per the route's units; the output includes whole units, revenue, margin per unit, and margin ratio.
Worked example
With $50,000 fixed costs, $30 variable cost per unit, and $50 selling price, contribution margin is 50 - 30 = $20. Break-even units are ceil(50,000 / 20) = 2,500, and break-even revenue is 2,500 x $50 = $125,000. The contribution-margin ratio is 20 / 50 = 40%.
How to interpret the result
The break-even point is the sales volume at which contribution margin covers fixed costs before profit. Selling one more unit above the rounded threshold creates contribution toward profit only if the assumptions remain valid.
Common mistakes to avoid
Use variable cost rather than total cost per unit in the contribution calculation. Do not round the margin before dividing. Check that selling price exceeds variable cost; otherwise additional sales do not cover fixed costs under this model.
Assumptions and limitations
The engine assumes one product, constant price and variable cost, and fixed costs that do not change with volume. It ignores taxes, mixed product sales, discounts, capacity limits, step costs, returns, and demand response. A nonpositive margin returns zero units rather than a meaningful attainable break-even.