Solar & battery
Solar Installation Cost Calculator
Works installed cost, where what the quote excludes decides the final figure.
Result
A planning estimate, not a quote. Access, the age of the equipment, what is found once it is opened up and local labour rates all move the real figure, sometimes a long way.
Get a Free Business AuditHow the calculation works
Equipment, labour, racking and balance of system, permitting and interconnection, and overhead and margin, with the items commonly excluded identified separately: service panel upgrades, roof repair or replacement, trenching for ground mounts, and structural reinforcement.
What moves the number
- The core system cost.
- Service panel upgrade, if required.
- Roof condition and any work needed first.
- Site-specific items such as trenching or reinforcement.
Where this one goes wrong
Roof condition is the exclusion that costs customers most, because installing an array on a roof near the end of its life means removing and reinstalling the array when the roof is replaced, at substantial cost. Assess the roof before the array. Service panel capacity is the other common addition, and both belong in the survey and in the quote as identified items rather than appearing as change orders after the contract is signed.
Before you quote
- Assess roof remaining life before installing an array on it.
- Check service panel capacity at survey.
- List exclusions explicitly in the quote.
Questions
About this calculator
Should I replace my roof before installing solar?
If it is near the end of its life, almost certainly, because removing and reinstalling an array when the roof is replaced costs a substantial amount. Assessing remaining roof life before the array is the cheapest decision in the project.
What is commonly excluded from a solar quote?
Service panel upgrades, roof repair or replacement, trenching for ground mounts and structural reinforcement. Each should be identified at survey and listed in the quote rather than appearing as a change order after signing.
Why do final costs exceed the quote?
Almost always one of the excluded items turning out to be required. That is a survey failure rather than a pricing one, and the fix is a thorough site assessment that identifies them before the customer has committed.
The formula
total = hours x people x rate + parts + call-out, then sales tax
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How to use this calculator
- Hours on site (h). Enter your own figure; the page starts at 32 h.
- People needed. Enter your own figure; the page starts at 1.
- Labour rate charged ($). Enter your own figure; the page starts at $105.
- Parts and materials ($). Enter your own figure; the page starts at $12,500.
- Call-out or diagnostic fee ($). Enter your own figure; the page starts at $95.
- Sales tax (%). Leave at zero if you are quoting before tax.
The result updates as you type, so you can try a figure, see what it does to estimated total, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Hours on site | 32 h |
| People needed | 1 |
| Labour rate charged | $105 |
| Parts and materials | $12,500 |
| Call-out or diagnostic fee | $95 |
| Sales tax | 0% |
What comes out
| Result | Value |
|---|---|
| Estimated total main result | $15,955 |
| Labour | $3,360 |
| Before tax | $15,955 |
| Sales tax | $0 |
About $15,955: $3,360 of labour, $12,500 of parts and a $95 call-out.
How sensitive the answer is
Holding everything else steady and changing only labour rate charged, this is what happens to estimated total. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Labour rate charged ($) | Estimated total |
|---|---|
| $53 | $14,291 |
| $79 | $15,123 |
| $105 example above | $15,955 |
| $158 | $17,651 |
| $210 | $19,315 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Hours on site (h)
- Measured in h, between 0 and 400, starting at 32 h.
- People needed
- A number, between 0 and 40, starting at 1.
- Labour rate charged ($)
- A money amount, starting at $105.
- Parts and materials ($)
- A money amount, starting at $12,500.
- Call-out or diagnostic fee ($)
- A money amount, starting at $95.
- Sales tax (%)
- Leave at zero if you are quoting before tax.
What the results tell you
| Result | What it is |
|---|---|
| Estimated total | The headline result. A money figure. |
| Labour | A money figure. |
| Before tax | A money figure. |
| Sales tax | A money figure. |
A design still needs a site visit
Output and sizing figures use the assumptions you enter, not measured irradiance, shading or roof orientation at your address. Real production depends on all three, plus inverter behaviour and local interconnection rules.
Estimating is the easy part
The jobs you never hear about cost more than the ones you mis-measure. BDEVY builds the marketing, systems and automation that bring them in.