The One Number That Tells You How Close You Are to Real Trouble

Two businesses. Same size tier. Same $650,000 a year in revenue.

One of them could survive a genuinely bad quarter without blinking. The other is one slow month away from operating at a loss.

If you only looked at revenue, you'd never know which was which. By the end of this article, you will — because you'll know how to calculate the number that actually tells the difference: break-even distance.

The two businesses below are illustrative composites, not real business data — built to demonstrate the math, not to represent actual companies.

First, What "Break-Even" Even Means

Think about a personal bank account.

Every month, money comes in (income) and money goes out (bills). If the two are exactly equal, your balance never moves. You're not gaining, you're not losing. You're break-even.

• If income beats your bills, your balance grows — you're above break-even.
• If your bills beat your income, your balance shrinks — every month, it gets worse. You're below break-even.

A business works the same way. Break-even is the point where revenue and costs are perfectly equal. It's the edge your business stands on. Everything you earn past that edge is your cushion for when a bad month hits.

Break-even distance is simply: how far past that edge you are, right now, expressed as a percentage.

Meet the Two Businesses

Both bring in $650,000 a year:

• Business 1 is a landscaping company — crew salaries, equipment leases, a small office, materials and fuel that scale with every job.
• Business 2 is a boutique fitness studio — instructor pay, a studio lease, a recent equipment loan, and class materials that scale with membership.

Same revenue. We're about to find out they are not remotely the same business — and the only way to see it is to actually run the numbers, step by step, for both.

Step 1: Work Out the Variable Cost %

Variable costs are anything that only happens because you made a sale — materials, commissions, ingredients, shipping.

Variable cost % = Total variable costs ÷ Total revenue

Landscaping company: $260,000 in materials, fuel, and subcontractors on $650,000 in revenue. $260,000 ÷ $650,000 = 40%

Fitness studio: $97,500 in class materials and software on the same $650,000 in revenue. $97,500 ÷ $650,000 = 15%

Already a real difference: 60 cents of every landscaping dollar is "free" after variable costs, versus 85 cents for the studio. The studio looks like the stronger business so far.

Step 2: Turn That Into Contribution Margin

Said plainly: contribution margin is how much you have left over to pay your fixed bills, once the variable cost of the sale itself is covered.

Contribution margin = 1 − Variable cost %

Landscaping: 1 − 0.40 = 60%
Fitness studio: 1 − 0.15 = 85%

So for every $1 of revenue, the landscaping company has 60 cents left to put toward its fixed bills; the studio has 85 cents. Still looks like the studio is winning.

Step 3: Add Up Fixed Costs — Properly

This is where it flips. Fixed costs are what you pay no matter what: rent, salaries, insurance, loan payments, subscriptions.

Landscaping company: $310,000 a year — crew, equipment leases, insurance, office.

Fitness studio: $380,000 in instructor pay, lease, and standing overhead — plus a recent equipment upgrade, financed at $155,000 a year. Owners almost always leave financed purchases like this out of the calculation, because they don't show up on a weekly report. Real fixed costs: $535,000.

Step 4: Calculate Break-Even Revenue

Break-even revenue = Fixed costs ÷ Contribution margin

Landscaping: $310,000 ÷ 0.60 = about $517,000
Fitness studio: $535,000 ÷ 0.85 = about $629,000

Step 5: Calculate Break-Even Distance

Break-even distance = (Current revenue − Break-even revenue) ÷ Current revenue × 100

Put simply: how far your sales could fall before you start losing money.

Landscaping: ($650,000 − $517,000) ÷ $650,000 = about 21%
Fitness studio: ($650,000 − $629,000) ÷ $650,000 = about 3%

The Reveal

The business that looked stronger at every earlier step — lower variable costs, higher contribution margin — turns out to have almost no cushion at all. One slow month, a dip in sign-ups, an unexpected repair, and the fitness studio is operating at a loss. The landscaping company could absorb a genuinely bad quarter and barely feel it.

Rule of Thumb

Break-even distance	What it means
Under 10%	One slow month can tip you into a loss
10–20%	Above break-even, but thin — a bad quarter will hurt
20%+	You can absorb a genuinely bad quarter without real damage

Explain It Like I'm 4

Both businesses make the same amount of money: $650,000.

But before either business gets to keep any of that money, some of it has to be spent right away — just to make the sale happen. The landscaping company spends more per job. The fitness studio spends less per class.

So the studio looks better here — it gets to keep more of every dollar.

But then comes the part that has nothing to do with sales: the bills that show up every single month no matter what. And it turns out the studio's bills are much bigger than the landscaping company's bills.

So even though the studio keeps more money from each sale, almost all of it gets swallowed by its bigger bills. There's barely anything left over. The landscaping company keeps less money per sale, but its bills are small enough that it still has plenty left over.

Keeping more money from each sale doesn't help you if your bills are big enough to eat it all anyway. That's why the business that looked stronger turned out to be the one in more danger.

This might sound complicated written out, but it's actually easier to see than to explain — pull up a basic P&L (profit & loss statement) and just look at the flow-through.

A Basic P&L Makes This Visible

Landscaping company

Line	Amount
Revenue	$650,000
Cost of sales	$260,000
Gross profit	$390,000
Operating expenses	$310,000
Net profit	$80,000

Fitness studio

Line	Amount
Revenue	$650,000
Cost of sales	$97,500
Gross profit	$552,500
Operating expenses	$535,000
Net profit	$17,500

Same revenue at the top of both P&Ls. But look at how much survives to the bottom: the landscaping company ends up with $80,000 in breathing room. The studio — despite a bigger gross profit — ends up with just $17,500. That's basically its entire cushion. One bad month wipes it out.

You don't need to calculate a percentage to see this. Just pull up your own P&L and look at what's left at the bottom, relative to how big your business is. That's break-even distance, made visible.

Why This Number Gets Missed

Fixed costs are easy to under-count — not because the math is hard, but because the costs don't show up on a weekly report. Annual insurance, a loan payment, equipment financed over 12 months: none of these hit you weekly, so they quietly get left out. That's exactly how a business drifts from a healthy 20%-plus cushion to a dangerous single-digit one without anyone noticing — until a bad month exposes it.

Do It for Your Own Business

1. Add up total variable costs for the year, divide by revenue → variable cost %.
2. 1 − variable cost % → contribution margin.
3. List every fixed cost for the year, including the ones that don't bill monthly.
4. Fixed costs ÷ contribution margin → break-even revenue.
5. (Revenue − break-even revenue) ÷ revenue × 100 → break-even distance.

Or skip the spreadsheet — I built a free calculator that does this in about a minute: Break-Even Calculator → It asks for monthly figures, so divide your annual numbers by 12.

Frequently Asked Questions

What's a healthy break-even distance for a small business?
20% or higher. Under 10% means very little room for a slow month, no matter how strong revenue looks.

Is this the same as profit margin?
No. Margin is what you keep as a % of revenue. Break-even distance is how much cushion you have before profit disappears entirely — a business can have good margin and still be dangerously close to break-even if fixed costs are high.

How often should I check this?
Monthly at minimum — more often if revenue is seasonal, you've recently taken on a loan or big fixed cost, or one client makes up a large share of revenue (see: customer concentration).

What do I do if I'm close to break-even?
Either grow revenue past the line, or cut the fixed costs pushing it up. Check your margin and cash runway too — they usually tell you which lever matters more for your business.

Related tools: Cash Runway · Customer Concentration Risk · Valuation Estimator
Related reading: The 4 Numbers I Check Every Monday Morning · Is Your Business Actually in Trouble?

Profit Lights provides an educational estimate only and does not provide a certified, professional, accounting, tax, legal, or investment assessment.

About Me

I'm Michael Philippou, co-founder of Big Love, a plant-based ice cream business in Santa Monica I've been running with my wife Victoria for over ten years. Before ice cream, I was a lawyer. I write about the real, unpolished lessons of running a small business — no gurus, no hype, just what's actually worked and what hasn't — at profitlights.com, where you'll also find a few free tools and the rest of my writing. You can find more of these stories on my YouTube channel, Real Business Real Lessons, or connect with me on LinkedIn.