Break-even: the revenue line where you stop losing money

Every month you cover the same set of costs whether you sell a lot or a little — rent, payroll, software, insurance. Break-even is the single revenue number that tells you exactly how much you need to sell to cover all of it, with nothing left over and nothing missing. Below that number you're losing money. Above it, you're making it. Knowing where that line sits changes how you price, who you hire, and what you bet on next.

The reason this matters is that "are we profitable?" is usually answered too late — after the month closes and the books are done. Break-even lets you answer it in advance. It turns a vague worry into a target you can put on a whiteboard and steer toward.

To get there, you need to split your costs into two buckets and learn one simple piece of math. It takes about ten minutes, and it pays off every time you make a money decision after that.

Fixed costs, variable costs, and contribution margin

Fixed costs are the ones that don't move with sales volume — your $20,000 a month in rent, salaries, and subscriptions stays $20,000 whether you sell one unit or a thousand. Variable costs move with each sale: materials, payment processing fees, shipping, the hourly labor tied directly to making the thing.

Contribution margin is the gap between your price and your variable cost on a single unit — the amount each sale "contributes" toward covering fixed costs. If you sell something for $50 and it costs you $20 in variable cost to deliver, your contribution margin is $30 per unit. That $30 is what's left to chip away at your fixed costs. Once enough units have each thrown in their $30 to cover all the fixed costs, every additional sale becomes profit.

The two formulas and a worked example

There are only two formulas, and they answer the same question in different units. Break-even in units is fixed costs divided by contribution margin per unit. Break-even in revenue is fixed costs divided by your contribution-margin ratio (that's contribution margin as a percentage of price).

Run the numbers from above. Fixed costs are $20,000 a month. You sell at $50, with $20 of variable cost, so contribution margin is $30 per unit. Break-even units = $20,000 ÷ $30 = about 667 units. To get the revenue figure, your contribution-margin ratio is $30 ÷ $50 = 60%, so break-even revenue = $20,000 ÷ 0.60 = about $33,333. Sell 667 units, bring in roughly $33,000, and you've exactly covered everything. Unit 668 starts earning you money.

Putting it to work in real decisions

Break-even is not a one-time calculation you file away — it's a lens you point at choices. The most useful one is the hire question. Bringing on a $7,000-a-month employee adds $7,000 to fixed costs, pushing them to $27,000. Divide by the same $30 contribution margin and your break-even jumps from about 667 units to 900. The real question isn't "can we afford the salary?" — it's "can we reliably sell 233 more units a month to pay for it?"

The same lens sharpens other calls:

• Pricing: nudging the price from $50 to $55 lifts contribution margin to $35 and drops break-even to about 572 units — a small price change moves the line a lot.
• New products: estimate the new line's fixed costs and contribution margin, and you'll know how many units it must sell before it stops being a drain.
• Discounts and promotions: a deeper discount cuts contribution margin, so check how many extra sales you'd need just to stay even.

One more idea worth carrying around: margin of safety. That's the gap between your actual sales and your break-even point. If you're running at $50,000 in revenue and break-even is $33,000, your margin of safety is $17,000 — sales could fall about a third before you start losing money. A thin margin of safety means a slow month hurts; a fat one means you can take a punch.

Pull your last full month, sort costs into fixed and variable, and calculate your break-even today. Once you know that number, write it on the wall — and recheck it every time you're tempted to raise a price, sign a lease, or add a head.