The 5 Numbers Every HVAC Owner Should Check Monthly (And Most Don't)

 

Most HVAC business owners know one number: how much came in this week. Maybe they also track what's owed on the truck or what payroll runs. But there are five specific numbers that tell you whether your business is actually healthy, and the owners who check them every month consistently run tighter, more profitable operations than those who don't.

This isn't a lecture on accounting. You didn't start your business to stare at spreadsheets. But you did start it to make money and keep it, so here are the five numbers worth knowing. They take about 20 minutes to pull once you have a system in place.

Number 1: Gross Profit Margin

Gross profit margin is what's left from your revenue after you subtract the direct cost of doing the work. That means labor, parts, refrigerant, and anything else that goes directly into completing a job.

Formula: (Revenue - Direct Job Costs) / Revenue = Gross Profit Margin

For most HVAC businesses, a healthy gross profit margin lands somewhere between 40 and 55 percent. If yours is running below 35 percent, you're either underpricing jobs, over-relying on high-cost subcontractors, or absorbing too much in materials without marking them up properly.

The reason this number matters monthly is that it shifts. Summer margins often look great because volume is up. Winter can compress them fast, especially if you're running fewer jobs but still paying your techs. Watching this monthly tells you whether your pricing is holding up across different conditions.

Number 2: Accounts Receivable Over 30 Days

This is the list of customers and commercial accounts that owe you money and have for more than a month. It's one of the most common places HVAC businesses quietly bleed cash.

You might have a strong month in revenue on paper and still feel broke, because the invoices haven't been collected. Residential customers usually pay at job completion, so this problem tends to show up more with property managers, HOAs, and light commercial accounts that run net-30 or net-60 terms.

Check this number monthly: How much is owed to you that's more than 30 days old? That's cash sitting in someone else's bank account.

If you see the same names appearing on this list every month, that's a collections conversation you need to have. A bookkeeper who's tracking this for you will flag it before it becomes a 90-day problem.

Number 3: Job Costing Variance

This one is underused and possibly the most valuable number on this list. Job costing variance is the difference between what you estimated a job would cost to complete and what it actually cost.

If you quoted a replacement at $3,200 and walked away with $2,600 after labor and materials, that's a $600 variance. Do that across ten jobs a month without noticing, and you're leaving serious money unaccounted for.

Common causes of negative variance: jobs running longer than estimated, technicians not logging hours accurately, material overruns, return trips to get parts, and warranty callbacks on work that should have been billed.

You don't need to track every single job this way immediately. But picking your top five highest-revenue job types and running the numbers monthly will tell you quickly which services are actually making money and which ones are eating it.

Number 4: Net Cash Position (Not Net Income)

Your P&L might show you made $18,000 in profit last month. But if payroll hits tomorrow and your checking account has $4,000 in it, the P&L doesn't help you. Net cash position is the real number.

Net cash position means: what is actually in the bank right now, net of any known upcoming obligations in the next 14 days. That includes payroll, any loan payments, vendor invoices that are due, and estimated quarterly tax deposits if you're approaching that deadline.

Profitable on paper. Broke in practice. This is the most common financial crisis in small trades businesses, and it's almost always preventable.

Checking this number monthly, and ideally weekly, gives you enough runway to act before you're scrambling. A 90-day cash flow projection built on your actual numbers takes this a step further and lets you see problems coming two or three months out.

Number 5: Revenue Per Technician

If you run multiple technicians, this number tells you how efficiently each one is generating revenue relative to what they cost you.

The calculation is straightforward: take the revenue directly tied to each tech's jobs in a month and divide it by their total compensation cost for that same period, including payroll taxes and benefits. A tech bringing in $22,000 in job revenue and costing you $6,500 is performing very differently than one bringing in $11,000 at the same cost.

This isn't about penalizing slower technicians or ignoring factors outside their control, like truck breakdowns or assignment geography. It's about spotting patterns over time. A tech who consistently runs below average might need additional training, better dispatching, or closer attention to how jobs are being assigned.

It also helps you make expansion decisions. Before adding a fourth truck, you want to know that your current three are running efficiently.

How to Actually Pull These Numbers

If your books are in Xero and organized correctly, you can pull most of these in under 30 minutes once a month. Gross margin comes from your P&L. AR aging is a standard report in any accounting system. Job costing requires either a field service app that integrates with your books or a simple tracking sheet that your bookkeeper maintains.

The hard truth is that most HVAC owners aren't pulling these numbers because the books aren't clean enough to trust, or because no one has set up the reporting structure to make it easy. That's the problem a bookkeeper who understands your industry can solve.

If you're already using Xero and want to know how your numbers actually stack up, that's a 30-minute conversation worth having.

About 911 Bookkeepers

We're the financial first responders for HVAC contractors and trades businesses in Louisiana. When your books are on fire, you call 911. Reach out at jbrewer@911bookkeepers.com or visit www.911boo