Break-Even Point Calculator (revenue & units)

Understanding the break-even point calculator — concept and principle

The break-even point is the sales level at which total revenue exactly covers total costs, so profit is zero. Below it you make a loss; above it every extra unit adds profit. Founders, shop owners and managers use it to test whether a business plan is realistic, to set prices and to see how much room there is before a slowdown causes losses.

How it is calculated

• Contribution margin per unit = price − variable cost per unit.
• Break-even units = fixed costs ÷ contribution margin per unit, rounded up to a whole unit.
• Contribution margin ratio = (price − variable cost) ÷ price × 100.
• Break-even revenue = fixed costs ÷ contribution margin ratio.

Fixed costs are costs for the period (here a month) that do not change with volume, such as rent and salaries. Variable cost per unit rises with every unit sold, such as materials, packaging and payment fees. The calculator works with any currency.

The principle

Each unit sold brings in its price but also uses up its variable cost; what remains, the contribution margin, is the amount that unit contributes toward fixed costs. Once enough units have contributed to pay all fixed costs, the business stops losing money. This is the core of cost-volume-profit (CVP) analysis taught in management accounting. It assumes a constant selling price, a constant variable cost per unit and fixed costs that stay fixed across the range you are studying.

Worked example

1. Inputs: fixed costs $20,000 per month, price $50, variable cost $30 per unit.
2. Contribution margin = $50 − $30 = $20.00 per unit.
3. Break-even units = $20,000 ÷ $20 = 1,000 units per month.
4. Contribution margin ratio = $20 ÷ $50 × 100 = 40%.
5. Break-even revenue = $20,000 ÷ 0.40 = $50,000.00, the same as 1,000 × $50.

How to read the result

Compare the break-even volume with what you can realistically sell. The margin of safety, (expected sales − break-even sales) ÷ expected sales, shows how far sales can fall before losses start; if you expect 1,250 units, the margin of safety is 20%. A high contribution margin ratio means profit grows quickly once you pass break-even. To lower the break-even point, raise prices, cut variable costs or reduce fixed costs.

Common mistakes

• Putting fixed costs into the variable cost per unit, or the other way round.
• Forgetting per-unit fees such as card processing, platform commission or shipping.
• Mixing periods, for example yearly fixed costs with a monthly sales plan.
• Not rounding break-even units up; you cannot sell a fraction of a unit.

Frequently asked questions

What if the price is lower than the variable cost?

The contribution margin is negative, so each sale adds to the loss and there is no break-even point. You must raise the price or cut variable cost.

How do I include a profit target?

Add the target profit to fixed costs: units needed = (fixed costs + target profit) ÷ contribution margin.

Sources: Charles T. Horngren, Srikant M. Datar and Madhav V. Rajan, Cost Accounting: A Managerial Emphasis (Pearson)