Most installers answer this question forward: pick a lead volume, hope it produces work. The arithmetic only behaves if you run it backwards, from revenue to installs to leads.
Here is the short version, and then the part that makes the short version dangerous.
The short answer
For ten installs a month on purchased shared leads, budget for roughly 125 to 200 leads, depending where your close rate sits in the 5% to 8% band.
That is the number. The rest of this is why using it alone will get your budget wrong.
Step 1: the arithmetic
Three inputs, in this order.
Average contract value. The average installed residential system in the United States is roughly 12 kW. At 2026 pricing of $2.41 to $3.34 per watt, national average near $2.58, that is about $30,500 per contract. If you mostly sell the 7 to 8 kW systems that match actual household usage, your number is closer to $18,000 to $22,000 and every calculation below shifts accordingly.
Installs needed. Revenue target divided by contract value.
Leads needed. Installs divided by overall close rate.
| Revenue target | Installs at $30,500 | Leads at 6% | Leads at 8% |
|---|---|---|---|
| $150,000 | 5 | 83 | 63 |
| $300,000 | 10 | 167 | 125 |
| $600,000 | 20 | 333 | 250 |
| $1,000,000 | 33 | 550 | 413 |
The close rate is doing more work in that table than anything else. Two percentage points is the difference between 167 leads and 125 for the same revenue, which is a 25% swing in media budget from a variable that costs nothing to improve.
Step 2: where the 6% comes from
Overall close rate is not one number, it is three multiplied together.
| Stage | Shared lead | Exclusive lead |
|---|---|---|
| Contact rate | 50% to 70% | 50% to 70% |
| Appointment set rate | 25% to 40% | 40% to 60% |
| Consultation to signed | 15% to 25% | 15% to 25% |
| Compounded | ~5% to 8% | ~10% to 15% |
Two things fall out of this.
The middle row is the one you control. Contact rate is mostly a function of the list and how fast you dial. Close rate from consultation is a function of your offer and your competition. Set rate sits squarely with your office, and it varies by a factor of two between the two products, which is most of the reason exclusive leads convert better.
And the last row explains the proposal problem. A 6% close rate means roughly 16 proposals per signed job. Solar proposals are not quick quotes: roof imagery, shading analysis, production modelling, financing options. That labour scales with lead volume, not with revenue.
Step 3: the number that breaks the budget
Now the part most calculators skip.
Take the $300,000 month. Ten installs, 167 shared leads at $60 each. Media cost: $10,000, about 3.3% of revenue. Comfortable.
Except the published benchmark for acquiring one residential solar customer in 2026 is roughly $5,880. Ten installs at that rate is $58,800, about 19% of revenue.
By the numbers
The same ten installs cost $10,000 by lead price and $58,800 by acquisition benchmark. Both figures are accurate. The gap of roughly $48,800 is everything the lead math leaves out.
That gap is not a rounding error, it is most of your marketing cost. It contains:
- Sales salary and commission across 167 leads, 50-ish appointments and 16 proposals
- Design and engineering labour on every proposal that does not close
- No-shows and unworked leads, which are paid for at full price
- Fallout between signature and install, which is specific to this trade
Budget from the lead price and you will be short. Budget from the acquisition benchmark and the number will look alarming but survive contact with reality.
We build the model on your actual close rate and contract value rather than industry averages, because a 2% error in close rate moves the lead target by a quarter. If you do not have those numbers instrumented yet, that is where we start.
Step 4: plan on installs, not signatures
Solar has a structural feature that HVAC and plumbing do not. In most trades, a signed job is done that week. In solar, a signature is the beginning of permitting, interconnection, financing approval and a cooling-off window in which homeowners reconsider.
Some share of signed contracts never becomes an installed system. That share is real, it varies by market and financing mix, and it means a lead plan built on signatures will overstate delivered revenue.
Build the model on installed jobs, then work back up through your own signature-to-install ratio. If you do not know that ratio, it is the single most valuable number to start tracking this quarter, and it requires a system that follows a job from first contact through to invoice rather than stopping at the sale. The practical setup is covered in CRM vs field service software for solar.
Step 5: seasonality makes the monthly average a fiction
A 167-lead monthly target implies twelve identical months. No solar year works that way, and 2026 works less that way than usual, because demand was pulled forward into the 25D deadline in late 2025.
Two adjustments:
Buy against capacity, not the calendar. Equipment lead times of four to six weeks plus schedule slip mean the leads that fill a given install week are bought roughly two months earlier.
Do not flatten the spend. The months when competitors withdraw are the cheapest auctions of the year, and they coincide with peak utility bills. We go through the reordered calendar in best time to advertise solar.
What to do when the number is unaffordable
Frequently the honest calculation returns a lead volume the business cannot fund. That is information, not failure. Three levers, in order of payback.
- Raise set rate. Ten points of appointment rate moves cost per install more than any negotiation on lead price, and it costs nothing but coaching and speed to lead.
- Raise contract value. Storage attachment is the obvious route, and a record 45% of Q1 2026 residential installs already included it. A larger average contract lowers the install count needed for the same revenue.
- Change the mix. Referrals run $300 to $600 per acquired customer against $800 to $1,500 for digital leads. They are slow to build, which is the argument for funding that work while purchased volume still carries the schedule. Solar lead generation without buying leads covers the lists worth building.
What does not work is buying more leads at a broken close rate. At 4% instead of 8%, every lead you add costs twice as much per install and adds proposal labour to a team already losing. Why are my solar leads not converting is the better place to start if that is the situation.
The one-page version
- Monthly revenue target, divided by average contract value, equals installs.
- Installs divided by overall close rate equals leads. Use 6% for shared, 10% for exclusive, until you have your own number.
- Multiply leads by lead price for media cost. Multiply installs by acquisition benchmark for true cost. Budget the second.
- Convert installs to signatures using your own fallout ratio, then buy against that.
- Shift the lead-time lag two months earlier than the install month you are filling.
- Before increasing volume, check whether ten points of set rate would have got you there for free.