Business Calculators
Combine fixed costs, variable costs and price per unit to find the volume and revenue you need to break even — plus what it takes to hit a target profit.
Overview
This free break-even calculator finds the volume at which a business stops losing money. Enter your fixed costs, your price and your cost per unit, and it shows the units and the revenue you need — plus what it takes to reach a target profit and how far sales could fall before you are in trouble.
The number that does the work is the contribution margin: price minus variable cost, or what each individual sale puts towards the fixed costs. Break-even is simply fixed costs divided by that figure, and almost every mistake people make with it comes from putting a cost on the wrong side of the division.
Units are rounded up rather than to the nearest whole number. A break-even of 1,234.2 units means 1,234 units still lose money, so the honest answer is 1,235. Rounding down would produce a target that does not do the one thing the target exists for.
Where the contribution margin is zero or negative there is no break-even point at all, and the tool says so rather than showing a number. That is the most valuable answer it can give: if every sale loses money, volume makes the loss bigger and only the price or the cost can fix it.
Step by step
Everything that does not change with volume for the period — rent, salaries, software, insurance.
The difference between them is the contribution: what each sale puts towards the fixed costs.
The units and revenue needed to break even, plus what happens if the price or the variable cost moves.
Background
A fixed cost does not change with how much you sell. Rent is the same whether you have a good month or a terrible one; so are salaries, insurance, software subscriptions and the accountant. A variable cost is incurred per sale — materials, packaging, shipping, payment processing, sales commission. Everything in a break-even calculation depends on which side a cost falls, and the whole difficulty is that some costs genuinely sit in between.
The mechanism is straightforward once the split is right. Each sale earns its price and immediately spends its variable cost; what is left over is the contribution, and it goes towards paying off the fixed costs. Break-even is the point where the accumulated contribution finally equals the fixed costs, so the arithmetic is fixed costs ÷ contribution per unit. Past that point the fixed costs are already paid, and every additional unit contributes its full margin straight to profit — which is why businesses with high fixed costs and thin variable costs are so profitable once they get past the line and so painful before it.
The critical case is a contribution margin that is not positive. If a unit costs more to deliver than it sells for, no volume helps: the loss grows with every sale, and a business in that position cannot grow its way out. This sounds obvious stated plainly and is remarkably easy to miss when the variable costs are spread across several categories and nobody has added them up in one place.
The other thing worth understanding is how sensitive break-even is to price. The entire price change lands on the contribution margin, so a small cut is a large proportional hit. On a product priced at 50 with 30 of variable cost, a 20% discount takes the price to 40 and the contribution from 20 to 10 — the volume needed to break even doubles. That is the arithmetic behind why heavy discounting so often fails to pay for itself.
Finally, break-even is a snapshot rather than a forecast. It assumes the price holds across every unit, that variable costs do not change with scale, and that fixed costs stay fixed over the range you are considering. All three assumptions eventually break — bulk discounts, volume pricing, a second warehouse — so it is a decision tool for a particular period and a particular scale, not a model of the business.
Reference
Three inputs are needed and two more make the answer actionable. Nearly all the error lives in the first three, and specifically in deciding which costs are fixed.
Fixed costs
Everything that does not change with volume over the period: rent, salaries, insurance, software, professional fees, loan interest. Understating these is the most common error and it flatters the result, which is why it survives so long unnoticed.
Required
Price per unit
What a customer actually pays, excluding tax you collect on someone else's behalf. Use the price after routine discounting rather than the list price, or you are calculating break-even for a sale that does not happen.
Required
Variable cost per unit
Everything incurred because that unit sold: materials, packaging, shipping, payment fees, commission, per-unit licensing. Each of these is individually small and collectively decisive, since they come straight out of the contribution.
Required
Target profit
Optional. Added to the fixed costs before dividing, because profit behaves exactly like another cost you have to cover. This is usually the more useful figure — breaking even is a floor, not a plan.
Optional
Expected units
What you realistically expect to sell, used for the margin of safety. It turns break-even from an abstract threshold into a statement about how much room the plan has before it fails.
Optional
Payment processing fees
Variable, always, and routinely forgotten. Two or three percent of the price sounds trivial until you notice it comes out of the contribution rather than the revenue — on a thin margin it can be a tenth of it.
Optional
Your own time
Fixed if you draw a fixed salary, variable if you are paid per unit of work. Service businesses often leave it out entirely, which makes break-even look achievable at a volume that would require working every hour there is.
Optional
The period
Fixed costs are always for a period — a month, a quarter, a year — and the break-even volume is for that same period. Mixing annual fixed costs with a monthly sales expectation is an easy error and a factor-of-twelve one.
Optional
The range the numbers hold over
Break-even assumes costs stay fixed and prices stay constant. Both eventually break — another member of staff, a bigger unit, a bulk discount — so the answer is valid for a range of volumes rather than for all of them.
Optional
Who it helps
Before the first sale the only meaningful question is how many are needed to stop losing money. It converts a plan into a testable number, and the number is frequently large enough to change the plan — which is the point of doing it early.
Fixed costs are software, insurance and the income you have to draw; the contribution is your day rate less any direct project costs. The result is how many billable days a month keep the lights on, which is a more useful target than a revenue goal.
Variable costs multiply quietly — product, packaging, shipping, payment fees, marketplace commission, returns. Adding them up in one place and seeing the contribution that survives is often the most informative half-hour a small seller spends.
A price cut lands entirely on the contribution margin, so the volume needed rises much faster than the discount suggests. Working out the new break-even before the promotion is how you find out whether it can possibly pay for itself.
A new hire, a bigger unit, a piece of equipment. Each raises the break-even volume by a knowable amount, and knowing it converts the decision from a feeling about affordability into a sales target.
Break-even, contribution margin and margin of safety are the first three numbers a reader looks for, and being able to produce them with the assumptions stated is most of what makes a plan credible.
Do it properly
Do it as a list rather than from memory. The costs that sit awkwardly between the two — part-time help, tiered software, delivery — are exactly the ones that change the answer, and guessing tends to flatter the result.
List price is not what customers pay if you discount routinely, and break-even calculated on list is a threshold you never reach. Average realised price is the honest input.
Payment fees, packaging, returns and commission come straight out of the contribution rather than out of revenue. Individually forgettable, together enough to change the volume needed by a large fraction.
Breaking even is survival rather than a goal. Adding the profit you actually need turns the calculation into a sales target, and profit behaves exactly like another fixed cost in the arithmetic.
Being profitable at the expected volume matters less than how far sales could fall before you are not. A thin margin of safety is a warning even when this month looks fine.
The whole of a price change lands on the contribution margin, so break-even moves further than the price does. Doing the arithmetic first is what stops a discount that cannot pay for itself.
Monthly fixed costs give a monthly break-even. Mixing an annual cost base with a monthly sales figure is an easy mistake, and it is wrong by a factor of twelve in the comfortable direction.
Avoid these
Treating a variable cost as fixed
Anything incurred because a unit sold is variable — packaging, shipping, payment fees, commission. Putting them in fixed costs overstates the contribution margin and understates the volume you need, which is the error that feels like good news.
Leaving out payment processing and platform fees
Include them per unit. Two or three percent of the price is trivial against revenue and substantial against contribution — on a thin margin those fees alone can be a tenth of what each sale contributes.
Calculating on list price while discounting in practice
Use the average price actually realised. A break-even built on a price customers rarely pay describes a business you are not running, and the gap only shows up as a persistent shortfall against target.
Rounding break-even units down
Round up. A break-even of 1,234.2 units means 1,234 units still lose money, and a target that does not cover costs has no purpose. Precision below a whole unit is false precision anyway.
Expecting volume to fix a negative contribution margin
It cannot. If a unit costs more to deliver than it earns, every extra sale makes the loss larger. The price or the variable cost has to change first, and no growth plan substitutes for that.
Mixing annual fixed costs with monthly sales
Match the periods. Annual costs give an annual break-even volume, and comparing that with a month of expected sales makes the business look twelve times healthier than it is.
Treating break-even as a forecast
It is a threshold under stated assumptions, not a model. Fixed costs step up as you grow, unit costs move with scale, and prices change — so recalculate when any of those do rather than trusting last year's figure.
FAQ
The Break-Even Calculator is at the top of this page — free, no signup, nothing uploaded.
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