Solar & battery
Solar System Cost Calculator
Builds system cost from components, where the soft costs are a large share.
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 at burdened rates, racking and balance of system, permitting and interconnection fees, and overhead and margin, totalled and expressed per watt. Per watt is the comparable figure across system sizes, and the soft costs within it are a larger share than customers expect.
What moves the number
- Equipment cost per watt at current pricing.
- Labour, which varies with roof and electrical complexity.
- Permitting and interconnection fees by jurisdiction.
- Overhead and margin.
Where this one goes wrong
Cost per watt falls as system size rises because the fixed elements of permitting, mobilisation, survey and interconnection spread across more capacity, which is why small systems are expensive per watt and why a minimum job size exists. Jurisdiction also moves the figure substantially through permitting fees and inspection requirements, so a cost per watt from one territory does not transfer to another.
Before you quote
- Express cost per watt and note the system size it applies to.
- Price permitting and interconnection by jurisdiction.
- Use current equipment pricing rather than carried-forward figures.
Where the rules come from
Questions
About this calculator
Why are small solar systems expensive per watt?
Because permitting, mobilisation, survey and interconnection costs are largely fixed and spread across less capacity. That is also why installers maintain a minimum job size, since below it the fixed costs consume the margin entirely.
What share of cost is equipment?
Less than customers expect. Labour, permitting, interconnection, overhead and margin together are a substantial share, which is why cost per watt varies between installers and jurisdictions more than equipment pricing alone would explain.
Does cost per watt transfer between markets?
Poorly, because permitting fees, inspection requirements, labour rates and interconnection processes all differ by jurisdiction. A figure from one territory is a starting point rather than a benchmark for another.
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.