Break-Even Point Calculator

The underlying calculation

Break-even in units is fixed costs divided by contribution per unit. In revenue it is fixed costs divided by the contribution margin ratio. Both answer the same question in different units, and which you want depends on whether you plan in orders or in money.

Contribution per unit is price less variable cost. Fixed costs are everything that does not move with volume: rent, salaries, software, insurance. The line between them is not always obvious, and where a cost steps up at a capacity threshold it is fixed within a band rather than fixed absolutely.

Worked through

Fixed costs of $38,000 a month, a $45 average price and $29.52 of variable cost. Contribution is $15.48, so break-even is 38,000 ÷ 15.48 = 2,455 units, or $110,475 of revenue.

Raise the price by 8% to $48.60 and contribution becomes $19.08. Break-even falls to 1,992 units: 463 fewer, a 19% reduction, from an 8% price rise.

Cut variable cost by 8% instead, to $27.16, and contribution becomes $17.84 with break-even at 2,130 units. Both levers work; the price lever works harder because it raises contribution by the full amount while the cost lever raises it by the cost saving only.

Where it goes wrong

It assumes a single product or a stable mix. A business selling products with contribution from $4 to $40 has a break-even that moves with whatever happened to sell, and a single figure calculated from an average is accurate only if the mix holds.

Step costs break it more seriously. If passing 3,000 units a month requires a second warehouse or an extra shift, then fixed costs are not fixed across the range being modelled, and the break-even calculated below the step does not apply above it.

Making it useful

Compare it against current volume to get the margin of safety, how far sales can fall before the business loses money. That figure is more actionable than break-even itself, because it converts a forecast into a survival question.

Then recalculate it whenever fixed costs change. A new hire, a bigger unit, an annual software commitment: each raises break-even by its own amount divided by contribution, and knowing that number before committing is the point of having the calculation at all.

Break-even as a test before adding fixed cost

The most valuable use of break-even is prospective rather than retrospective. Before hiring, taking a larger unit, or committing to an annual contract, divide the new cost by contribution per unit and ask whether that many additional units are realistic.

A $3,000 a month hire at $15.48 of contribution needs 194 additional units a month to pay for itself. If the business currently does 2,500, that is an 8% volume increase, plausible. If it does 400, it is a 48% increase, which is a different proposition entirely and one worth being explicit about before the contract is signed.

Running the arithmetic this way turns hiring and commitment decisions from questions of confidence into questions of volume, which are far easier to argue about honestly.