Ecommerce Break-Even Calculator
Calculate exactly how many units you must sell each month to cover fixed costs and hit a profit target. Essential when launching a new product or evaluating a new sales channel.
About this calculator
The break-even point tells you the minimum sales volume at which total revenue equals total costs, producing zero loss. In e-commerce, every unit sold generates a contribution margin equal to the selling price minus the variable cost per unit and the marketing cost per unit: contributionMargin = sellingPrice − variableCostPerUnit − marketingCostPerUnit. Fixed costs—rent, software, salaries—must be covered before any profit is realized. The units needed formula is: units = ⌈(fixedCosts + targetProfit) / contributionMargin⌉. The ceiling function (⌈⌉) rounds up to the nearest whole unit, since you cannot sell a fraction of a product. Adding a targetProfit term lets you set a revenue goal, not just a survival threshold.
How to use
Say fixed costs are $3,000/month, variable cost per unit is $12, selling price is $35, marketing cost per unit is $5, and target profit is $1,000. Step 1 — contribution margin: $35 − $12 − $5 = $18. Step 2 — units needed: ⌈($3,000 + $1,000) / $18⌉ = ⌈$4,000 / $18⌉ = ⌈222.2⌉ = 223 units. You must sell 223 units per month to cover all costs and earn $1,000 in profit.
Frequently asked questions
What is the difference between break-even point and target profit units in ecommerce?
The break-even point is the sales volume at which revenue exactly covers all costs, leaving zero profit or loss. Target profit units go one step further by adding a desired profit amount to the numerator, so the result tells you how many sales you need to achieve a specific financial goal. For business planning, calculating target profit units is more useful because it ties sales volume to an actual income objective rather than just survival.
How does marketing cost per unit affect the ecommerce break-even calculation?
Marketing cost per unit—such as paid ad spend divided by units sold—reduces the contribution margin directly, meaning more units are needed to cover fixed costs. A product with a $20 contribution margin before marketing that costs $8 per unit to acquire has an effective margin of only $12. Tracking customer acquisition cost at the product level, rather than blending it across the store, gives a much more accurate break-even picture.
When should an ecommerce business recalculate its break-even point?
Recalculate whenever any major input changes: a supplier raises the cost of goods, shipping rates increase, you hire staff, or you launch a new ad campaign with a different cost-per-acquisition. Seasonal businesses should also recalculate before each peak period. Treating the break-even point as a static annual figure ignores cost drift and can lead to underpricing that seems profitable on paper but loses money in practice.