Solar & battery
Solar Installation Quote Calculator
Builds a quote, where what is written down prevents the dispute.
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
The priced estimate converted into a customer-facing figure with the scope stated: system size and equipment specified, what is included, what is excluded, what the production estimate assumes, and what triggers additional cost. The arithmetic is the estimate; the quote is the document.
What moves the number
- Equipment specified by make and model.
- Scope inclusions and exclusions.
- Production estimate and the assumptions behind it.
- What triggers additional cost.
Where this one goes wrong
Specifying equipment by make and model rather than by capacity is what prevents a substitution dispute later, and customers increasingly ask about it. Stating the production estimate with its assumptions, and stating what the system will not do, is the other protection: a customer who believed a grid-tied system would provide backup during an outage was told something, and the quote is where that is corrected rather than discovered during a storm.
Before you quote
- Specify equipment by make and model.
- State what the system will not do, including outage behaviour.
- List exclusions and what triggers additional cost.
Questions
About this calculator
What should a solar quote specify?
Equipment by make and model rather than capacity, the scope inclusions and exclusions, the production estimate with its assumptions, and what triggers additional cost. Each of those prevents a specific dispute that otherwise happens.
Why specify equipment by model?
To prevent a substitution dispute, since modules and inverters of the same capacity differ in efficiency, warranty and reputation. Customers increasingly ask about it, and a quote specifying only capacity leaves the question open.
Should a quote state what the system will not do?
Yes, particularly that a grid-tied system without storage provides no power during an outage. A customer who believed otherwise was told something, and the quote is the right place to correct it rather than during the next storm.
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.