Solar & battery
Solar Installation Estimate Calculator
Builds an install estimate, where the survey determines whether it holds.
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
Quantities and hours by task from the design, priced at current equipment and burdened labour rates, with permitting and interconnection fees and the overhead allocation. An estimate is only as good as the site information behind it, which is why the survey rather than the arithmetic is the determining step.
What moves the number
- Design quantities from the actual roof layout.
- Hours by task for the specific roof and electrical run.
- Current equipment pricing.
- Jurisdiction-specific fees and requirements.
Where this one goes wrong
An estimate produced from satellite imagery without a site visit misses roof condition, structural questions, service panel capacity, attic access and shading that imagery does not show, all of which change the price. Those are the items that turn an estimate into a change order. Where a remote estimate is given for speed, it should be stated as preliminary and subject to survey rather than presented as a firm price.
Before you quote
- Survey the site before giving a firm price.
- Label remote estimates as preliminary and subject to survey.
- Price at current equipment costs and burdened labour rates.
Questions
About this calculator
Can a solar estimate be done remotely?
Preliminarily, and it should be labelled that way. Imagery misses roof condition, structural questions, service panel capacity, attic access and real shading, all of which change the price, and those are the items that become change orders.
What does a good survey check?
Roof condition and remaining life, structural capacity, rafter layout, service panel capacity and available breaker space, the route from array to inverter to service, attic access, and shading across the day. Each of those can move the price or the design.
Why do estimates become change orders?
Because something the survey did not check turned out to matter. The change order is the symptom; the cause is a survey that was skipped or rushed, and no amount of contingency pricing substitutes for having looked.
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.