The most reliable way to set an HVAC marketing budget is to start from capacity: how many jobs your trucks can do, how many calls it takes to book them, and what those calls cost by channel. Percentage-of-revenue rules are easy to quote but ignore the thing that matters most, which is whether the trucks are full. This guide walks through the method and applies it to three companies at different stages.
All numbers below are invented round figures to illustrate the arithmetic. Swap in your own.
Step 1: work out your capacity in booked jobs
Capacity is the number of jobs your crew can complete in a month at a sensible pace, split by job type.
For service work, a simple version is:
trucks × service calls per truck per day × working days
For installs, count install days per crew per month instead, because one replacement can take a full day or more.
Don't count the jobs you'd do on your best week of the year. Count a normal week, with travel, callbacks and paperwork included. Then subtract the work you already get from repeat customers, maintenance agreements and referrals. What's left is the gap marketing needs to fill.
Step 2: convert the gap into calls
A booked job starts as a call, a text or an email. Not every one becomes a job.
calls needed = jobs to fill ÷ booking rate
Your booking rate is booked jobs divided by qualified enquiries, meaning real people asking about work you do in an area you serve. If your office books 6 of every 10 qualified calls, your booking rate is 60%.
This step is where many budgets go wrong. If the booking rate is low, the budget balloons, and the cheapest fix is usually on the phone, not in the ad account. Raising the booking rate from 50% to 70% cuts the calls you need by almost 30%.
Step 3: price the calls by channel
Each lead source has its own cost per qualified call. Use your own tracked numbers if you have them; if not, run a small test for a month before committing to a full budget.
| Channel | What it tends to bring | How cost behaves |
|---|---|---|
| Google Business Profile and reviews | Urgent local repair calls | Low cash cost, needs steady effort |
| Local Services Ads | Urgent calls from people comparing a few providers | Charged per lead, varies by market |
| Google search ads | Repair and replacement searches | Charged per click, rises with competition |
| Organic search and content | Research-stage and urgent searches over time | Slow to start, cheap per call once built |
| Meta ads and retargeting | Replacement buyers still deciding | Low per click, longer path to a booked job |
Multiply the calls you need from each channel by its cost per call, add the plan fee and tools, and you have a monthly budget built from the ground up.
Worked example 1: one truck
An established owner-operator works about 20 days a month and can handle four service calls a day, so about 80 jobs a month. Repeat customers and referrals already supply around 55.
- Gap to fill: 25 jobs.
- The owner books about 8 in 10 calls they actually answer, but misses roughly a third of calls while working. So the effective booking rate is closer to 53%.
- Calls needed: 25 ÷ 0.53 ≈ 47.
The lesson here isn't about ad budgets at all. Fix missed calls first, with text-back and a callback rule, and the effective booking rate rises toward 80%. Now only about 31 calls are needed, and a well-kept Business Profile with steady reviews may supply most of them. This is why our one-truck foundation starts with call coverage.
Worked example 2: a four-truck crew
Four trucks, 21 working days, about four service calls per truck per day, so roughly 336 jobs in a peak month. In shoulder months, existing customers and maintenance visits cover only around 180.
- Shoulder-month gap: about 156 jobs.
- The office books 65% of qualified calls.
- Calls needed: 156 ÷ 0.65 = 240.
If the Business Profile and organic search bring 90 of those, paid channels need to supply 150. At an illustrative $40 per qualified call, that's $6,000 of ad spend for a shoulder month, before the plan fee.
That's a big number for a four-truck company, which is exactly why maintenance agreements matter at this stage. If a late-winter campaign books 60 maintenance visits into April, the paid gap falls to about 90 calls, or $3,600. Our crew-stage service is built around that trade-off.
Worked example 3: a twelve-truck shop
Twelve trucks, split between eight service trucks and four install crews. Service capacity is about 670 jobs a month; install capacity is about 80 replacements.
At this size the budget needs two separate calculations, because a replacement lead is worth far more than a repair call and costs more to find.
- Service gap: existing customers cover about 450, so 220 jobs are needed. At a 70% booking rate, that's about 315 calls.
- Install gap: about half the replacements come from service technicians spotting failing equipment. The other 40 need marketing. If one replacement enquiry in three closes, that's 120 enquiries.
Replacement enquiries might cost $90 each through search and retargeting, against $35 for a service call, at illustrative rates. The install side alone is then about $10,800 a month, which is why full shops judge channels on revenue, not just on cost per lead. Our full-shop marketing service connects that reporting to your CRM.
Why cost per job rises as you grow, and how to pull it back
Most owners notice that marketing gets more expensive per job as the company grows. That's normal, and it has a cause.
Your cheapest work, from referrals, repeat customers and people searching your company's name, grows slowly. Your payroll grows in steps every time you add a truck. To fill the gap, you buy more competitive searches and reach people who've never heard of you. Each extra job costs a little more than the last.
Three things pull the blended cost back down:
- Maintenance agreements. Booked work that doesn't need new marketing every year, and a direct line to the replacement when the time comes.
- Repeat and referral systems. Review requests and follow-ups after every job, so each customer is more likely to come back and recommend you.
- Organic search and content. Slow to build, but cheap per call once it works. Roma Heating & Cooling, one of our HVAC clients, grew organic traffic by 400% over 12 months.
Common budgeting mistakes
- Copying a competitor's spend. Their trucks, service area and booking rate aren't yours.
- Leaving out the fixed costs. Plan fees, call tracking and software belong in cost per booked job.
- One number for twelve months. Build at least three budgets: peak, shoulder and off-peak.
- Funding a new city from the home budget. Keep expansion separate, as our second-city guide explains.
Putting it together
To build your own budget, you need five numbers: trucks, jobs per truck per day, working days, work already covered by existing customers, and your booking rate. Run them for a peak month and a shoulder month, and you'll know roughly what marketing needs to do and what it should cost.
If you don't have those numbers yet, finding them is the first piece of work. The growth-stage audit gathers them with you during the free trial, and the pricing page shows the plan fees to add on top.
Frequently asked questions
Why not just spend a percentage of revenue?
A percentage rule ignores capacity. A company can be under-spending in April and over-spending in January at the same percentage. Building the budget from the jobs your trucks can handle ties spend to something real.
What booking rate should I assume?
Use your own. Count last month's qualified calls and how many became booked jobs. If you don't track it, start tracking it now, and use a cautious estimate until you have a month of data.
Does the plan fee count as marketing spend?
Yes. When you calculate cost per booked job, include agency or plan fees, ad spend, call tracking and software. Otherwise the number flatters every channel.
Should the budget change by month?
Almost always. HVAC demand follows the weather, so a flat monthly budget overspends in peak weeks, when calls come anyway, and underspends in shoulder months, when trucks need help.