Break-Even Calculator

Fixed vs Variable Costs

Fixed costs remain constant regardless of how many units you sell: rent, salaries, insurance, and software subscriptions all continue whether you sell one unit or a thousand. Variable costs scale directly with production or sales volume — materials, payment processing fees, shipping, and sales commissions. Understanding this split is essential because it determines how your profitability scales: a business with high fixed costs and low variable costs has operating leverage — each additional unit sold after break-even contributes nearly its full price as profit. A business with high variable costs has lower leverage but also lower risk if sales drop.

Contribution Margin Explained

Contribution margin = revenue per unit − variable cost per unit. It represents what each unit sale "contributes" toward covering fixed costs and ultimately generating profit. If you sell a product for $50 with $20 in variable costs, your contribution margin is $30 (60%). Break-even units = fixed costs ÷ contribution margin per unit. Contribution margin is different from gross margin: gross margin includes all costs of goods sold (COGS), while contribution margin specifically isolates the variable portion. Both are useful; contribution margin answers "how many units to break even?" while gross margin benchmarks overall operational efficiency against industry norms.

The Break-Even Formula

Break-even analysis rests on two formulas:

Break-even units = fixed costs ÷ (unit price − variable cost per unit)
Break-even revenue = break-even units × unit price

The denominator of the first formula is the contribution margin from the section above — the amount each unit earns toward fixed costs once variable costs are covered.

A Worked Example

Your ecommerce shop has $4,000 of fixed costs each month. Your product sells for $80 with $30 of variable cost, so each unit contributes $50:

Break-even units = $4,000 ÷ ($80 − $30) = 80 units
Break-even revenue = 80 × $80 = $6,400 per month

Every unit beyond 80 contributes $50 of pure profit. At 130 units sold, monthly profit is (130 − 80) × $50 = $2,500, or $30,000 over a 12-month projection — before any seasonality you build into the assumption.

How to Use This Calculator

1. Enter the monthly total of all costs that stay the same whether you sell one unit or a thousand (rent, salaries, subscriptions).
2. Enter the variable cost per unit — materials, shipping, payment processing, commissions.
3. Enter your unit selling price. The calculator returns break-even units, break-even revenue, and the 12-month profit projection chart.

Using Break-Even Analysis for Pricing

Break-even analysis runs in both directions. Given a price, it tells you how many units you must sell. Given a target unit volume, it tells you the minimum price required to break even. This makes it a powerful pricing tool: if your break-even at $50 requires selling 500 units per month and your market research suggests you can only sell 300, you either need to raise the price, cut fixed costs, or reduce variable costs. Running break-even at multiple price points quickly surfaces the sales volume sensitivity of any pricing decision before you commit to a go-to-market strategy.

Margin of Safety

The margin of safety is the difference between your actual or projected sales and your break-even sales level — expressed as a percentage. If break-even is 500 units and you project selling 700, your margin of safety is 28.6%. This represents how much sales can decline before you start losing money. A high margin of safety (above 30%) indicates a resilient business with room to absorb unexpected drops in revenue. A low margin of safety (under 10%) means the business is vulnerable to small disruptions. Investors and lenders look at margin of safety alongside break-even when evaluating financial risk.