Break-Even Calculator for Ecommerce
How many units do I need to sell before I stop losing money?
Your numbers
Result
Break-even units
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How this is calculated
Break-even is the volume at which total contribution covers fixed costs. It is the number to know before committing to inventory, because it tells you whether your forecast is realistic or wishful.
- Contribution margin per unit = selling price − variable cost per unit
- Break-even units = fixed costs ÷ contribution margin per unit
- Break-even revenue = break-even units × selling price
- Units per month = break-even units ÷ months in the period
What to make of the number
The useful question is not whether break-even is reachable but whether it is reachable at a realistic conversion rate. If break-even needs 900 units a month and your category converts at 1.5%, you need about 60,000 sessions a month — which is a very different conversation about ad budget.
Frequently asked questions
What counts as a fixed cost?
Anything that does not change with the next unit sold: product development, photography, tooling, software subscriptions, retainers, rent and salaries. Inventory purchases are usually variable, not fixed.
What counts as a variable cost?
Everything that scales with each order: cost of goods, marketplace fees, fulfilment, shipping, payment processing and per-unit advertising. Getting this complete matters more than getting it precise.
What if my contribution margin is negative?
Then no volume will save you. Each additional unit increases the loss. The fix is on the cost or price side, not the volume side.
Should advertising be treated as fixed or variable?
Performance advertising tied to orders is variable. Brand spend and retainers behave more like fixed costs. Split them rather than lumping everything into one bucket.
How does break-even relate to payback?
Break-even tells you when cumulative profit turns positive. Payback tells you when your cash returns to your account. With inventory bought upfront, payback usually comes later, which is the constraint that actually kills growing stores.
Do the research before you commit inventory
SkuMath shows you the math. Helium 10 supplies the live Amazon data those calculations need as inputs — product demand, keyword volume, competitor reviews and profit tracking.