Calculate break-even units and revenue based on fixed and variable costs. Identifies margin of safety.

About the Break-Even Analysis

The break-even point is the sales level at which a business stops losing money and starts making it — the exact number of units where total revenue finally covers total costs. Knowing it turns pricing and volume from guesswork into arithmetic: you can state, with confidence, how many units you must sell each month just to keep the lights on before a single dollar of profit appears.

This analysis is essential before you launch a product, sign a lease, take on fixed staff, or set a price. It separates the two kinds of cost that behave completely differently — fixed costs that you owe no matter what, and variable costs that occur only when you make a sale — and reveals how much of each sale is actually left over to chip away at the fixed pile.

It also frames the flip side: your margin of safety, or how far current sales sit above the break-even line before you slide back into loss. That cushion is a plain-language measure of how much a downturn you can absorb.

Before you enter your numbers

Estimate fixed costs for one consistent period and variable cost per unit. Use the same period for planned sales.
Keep selling price and variable cost in the same units: per visit, per product, or per billable hour, not a mixture.

Assumptions and limits

The model assumes one representative unit, constant price and unit cost, and no step changes in capacity. A multi-product business needs an explicit sales mix.
If price is no greater than variable cost, there is no finite break-even point. The tool displays N/A for that condition.
The margin-of-safety comparison is fixed at an illustrative 250 units; it is not your sales forecast. The 600-unit scenario below is a manual extension of the formula.

Check your result

$10,000 fixed costs ÷ ($50 price − $30 variable cost) = 500 units. Revenue is $25,000. At 600 units the contribution is $12,000 and operating surplus before unmodeled costs is $2,000.

How the Break-Even Analysis works

You enter three inputs: Total Fixed Costs, Variable Cost per Unit, and Selling Price per Unit. From these the worksheet computes the contribution margin per unit = Selling Price − Variable Cost — the amount each sale contributes toward fixed costs and, eventually, profit. It also shows the contribution margin ratio, which is that margin divided by the selling price.

Break-even units = Fixed Costs ÷ Contribution Margin per Unit, rounded up to the next whole unit because you cannot sell a fraction of a product. Break-even revenue is simply that unit count multiplied by the selling price. Above that revenue line every additional unit drops its full contribution margin straight to profit.

The tool also illustrates a margin of safety against an assumed current sales level so you can see the buffer between where you are and where you would start losing money. Fixed costs must be genuinely fixed and variable costs genuinely per-unit for the result to hold; a mislabeled cost shifts the break-even point sharply.

Worked example

Take the defaults: Total Fixed Costs $5,000, Variable Cost per Unit $20, Selling Price per Unit $50. The contribution margin per unit is $50 − $20 = $30, and the contribution margin ratio is $30 / $50 = 60%. That means 60 cents of every sales dollar is available to cover fixed costs.

Break-even units = $5,000 ÷ $30 = 166.7, rounded up to 167 units. Break-even revenue = 167 × $50 = $8,350. So you must sell 167 units, generating $8,350 in revenue, before the business turns a profit; unit number 168 begins adding $30 of pure profit. If an assumed 250 units are currently selling, the margin of safety is 250 − 167 = 83 units, or about 33% — sales could fall by roughly a third before you hit break-even.

Tips & common mistakes

Be strict about which costs are fixed. Rent, insurance, and salaried staff are fixed; hourly labor tied to production and raw materials are variable. Sliding one into the wrong bucket moves your break-even point significantly.
If your contribution margin per unit is zero or negative, no volume will ever break you even — you must raise price or cut variable cost first, because selling more only loses money faster.
Recalculate whenever you add a fixed cost like a new hire or a bigger space; a jump in fixed costs raises the number of units you must sell just to stand still.
Use the contribution margin ratio to convert quickly between dollars and units — dividing any fixed-cost target by the ratio gives the revenue needed to cover it.
Aim for a comfortable margin of safety, not just clearing break-even; a business operating right at its break-even point has no cushion for a slow month.

Break-Even Analysis: frequently asked questions

What is the contribution margin and why does it matter?

Contribution margin is selling price minus variable cost per unit — the money each sale contributes toward fixed costs and then profit. On the defaults it is $30 per unit. It matters because break-even is simply fixed costs divided by this figure; a higher contribution margin means you break even on fewer sales.

Why does the break-even unit count round up?

Because you cannot sell part of a unit. Dividing $5,000 by $30 gives 166.7, but you need a whole 167 units to fully cover fixed costs, so the tool rounds up. Selling only 166 would leave you slightly short of break-even.

What is the margin of safety telling me?

It shows how far your current sales sit above the break-even point before you would start losing money. At 250 units against a 167-unit break-even, the safety margin is 83 units or about 33%, meaning sales could drop roughly a third before profit disappears.

How do I find the break-even in dollars instead of units?

Multiply break-even units by the selling price, or divide fixed costs by the contribution margin ratio. Both give $8,350 on the defaults. The dollar figure is handy when you sell many products and think in revenue rather than unit counts.

What if I sell several different products?

This single-product model works best for one item or a blended average. For a varied product mix, use an average contribution margin ratio across your sales, then divide total fixed costs by that ratio to estimate break-even revenue.

Use the result in your next decision

Cash Flow Forecast: Check whether collection timing can fund the sales needed to reach break-even.

Sources and further reading

These references explain the specified topic; they are not endorsements or evidence that a professional has reviewed this tool.

SBA: Break-even point — Documents contribution-margin break-even and its planning role.

Break-Even Analysis