Break Even Calculator for Ecommerce: Find Your Profitability Threshold 2026

What Is a Break-Even Point?

The break-even point is the number of units you must sell per month for total revenue to exactly cover total costs, both fixed (rent, subscriptions, payroll) and variable (product cost, shipping, fees per unit). Below break-even, the business loses money. Above it, every additional unit sold generates profit. Knowing your break-even transforms vague “are we profitable yet?” anxiety into a specific daily target: “we need to sell X units per day to cover costs.”

Break-even analysis is particularly valuable before committing to new fixed costs (hiring, warehouse lease, software subscriptions) because it shows exactly how many additional units those costs require. A $500/month software tool that saves 2 hours/week is worth it only if your contribution margin and sales volume can absorb the additional fixed cost without pushing break-even beyond achievable sales targets. The financial planning framework uses break-even as the foundation for growth investment decisions.

How to Use This Calculator

1. Monthly fixed costs: All recurring costs that don’t change with sales volume: rent, software subscriptions, insurance, loan payments, salaried payroll, platform fees. If you work from home, include allocated costs like internet and workspace. Don’t include variable costs (those go in the next field).
2. Selling price per unit: Your product’s retail price. If you sell multiple products at different prices, use your weighted average selling price (total revenue / total units) for a blended break-even, or run the calculator separately for each product.
3. Variable cost per unit: Everything that costs you money for each unit sold: product cost (COGS), shipping, packaging, payment processing fees (2.9% + $0.30), and marketplace fees if applicable. The margin calculator computes the precise variable cost per unit across all cost components.
4. Monthly ad spend: Advertising is technically a variable investment, but most stores run ads at a fixed monthly budget. Including it in break-even shows how many sales your ads need to generate to justify the spend. Set to $0 if you rely entirely on organic traffic.

How Break-Even Is Calculated

Contribution Margin = Selling Price – Variable Cost per Unit

Break-Even Units = Total Fixed Costs / Contribution Margin

Break-Even Revenue = Break-Even Units x Selling Price

Worked example

Fixed costs: $2,500/month (Shopify + tools + insurance + part-time VA). Ad spend: $1,000/month. Total fixed: $3,500. Selling price: $45. Variable cost: $18 (product $10 + shipping $5 + packaging $1.50 + processing $1.50). Contribution margin: $27 per unit. Break-even: $3,500 / $27 = 130 units/month = 4.3 units/day. At $45 per unit, that’s $5,850/month in revenue to break even. Everything above 130 units generates $27 profit per unit.

When to Use This Calculator (and When Not To)

Use it when evaluating whether a new product is viable at projected sales volumes, before adding new fixed costs (employee, lease, software), when setting monthly sales targets for profitability, and when deciding between business models with different cost structures (the model comparison should pair with break-even analysis for each model’s typical cost structure).

Don’t use it as your only financial planning tool. Break-even tells you the minimum viable volume but says nothing about cash flow timing (you might break even over 12 months but run out of cash in month 3), customer acquisition cost sustainability, or long-term profitability. The cash flow projection and the ad spend ROI calculator complement break-even with timing and channel-level profitability analysis.

Common Break-Even Calculation Mistakes

Forgetting to include all variable costs. Product cost alone isn’t the full variable cost. Shipping ($3 to $8), payment processing (2.9% + $0.30), packaging ($0.50 to $2), marketplace fees (8 to 15% on Amazon/Etsy), and return handling costs are all variable costs that reduce contribution margin. Missing $5 in variable costs on a $45 product inflates contribution margin by 23%, dramatically understating the real break-even point.

Treating ad spend as variable when it’s budgeted as fixed. If you spend $1,000/month on ads regardless of sales volume, it functions as a fixed cost for break-even purposes. If you scale ad spend proportionally with revenue (e.g., 20% of revenue), treat it as a variable cost by adding 20% of selling price to the variable cost per unit. The ROAS expectations determine whether treating ad spend as fixed or variable better reflects your actual spending behavior.

Using break-even as a growth target. Break-even is the survival line, not the goal. At break-even, you earn zero profit, zero owner’s salary (if not already in fixed costs), and zero reinvestment capacity. A healthy target is 2x break-even, which provides profit for the owner, cash reserve building, and reinvestment into growth. This calculator shows “Profit at 2x Break-Even” to illustrate the margin above the survival line.

Ignoring the time dimension. A break-even of 130 units/month is meaningless if your marketing generates only 30 units/month in the first 6 months while costs accumulate. Model the path to break-even: at current growth rate, how many months until you reach 130 units/month? Can your cash reserves sustain the business through those loss-making months?