Solar & battery
Solar Tax Credit Calculator
Works the value of a solar tax credit, where current eligibility has to be confirmed first.
Result
Incentives change, expire and differ by state, utility and tax position. Nothing here is tax advice: whether you can use a credit at all depends on your own liability, and a credit is not a rebate. Confirm what applies to you with a tax professional before it affects a purchase decision. A tax credit reduces tax owed, so it is worth nothing to somebody with no liability that year, and the carry-forward rules differ between federal and state programmes. Rebates usually reduce the cost basis the credit is calculated on, which this simplified version does not model.
Get a Free Business AuditHow the calculation works
The credit rate applied to eligible costs, with the result being a credit against tax owed rather than a payment. The eligible cost base, the rate, whether the credit is refundable and whether it carries forward are all set by the specific provision, and residential and business installations fall under separate provisions with separate rules.
What moves the number
- Which provision applies, residential or business.
- Whether the credit is currently available for your placed-in-service date.
- Eligible costs, which may exclude some items.
- Tax actually owed, since a non-refundable credit needs liability to offset.
Where this one goes wrong
Federal solar credits have been amended and curtailed by legislation, including changes to availability by placed-in-service date, so no figure here should be treated as current and the position must be confirmed with the IRS and a tax professional before relying on it. A credit is also not a rebate: a non-refundable credit requires tax liability to offset, so a household with little tax owed may not benefit as the headline rate suggests, and carryforward rules differ between provisions.
Before you quote
- Confirm current eligibility and rate with the IRS and a tax professional.
- Check whether you have sufficient tax liability to use the credit.
- Establish which costs are eligible before applying any rate.
Where the rules come from
Questions
About this calculator
Is there a federal solar tax credit right now?
The federal provisions have been amended and curtailed by legislation, with availability depending on the provision and the placed-in-service date, and residential and business credits are separate. The current position has to be confirmed with the IRS and a tax professional rather than assumed.
Is a tax credit the same as a rebate?
No. A credit offsets tax owed, so a household with little tax liability may not benefit as the headline rate implies. Whether it is refundable and whether unused amounts carry forward differ between provisions and change the real value.
Which costs are eligible?
That depends on the provision and has varied over time, with some associated work included and some excluded. Establishing the eligible base before applying any rate is necessary, and it is a question for a tax professional rather than an installer's estimate.
The formula
credit = eligible cost x credit rate; usable this year is capped by your tax liability
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How to use this calculator
- Eligible system cost ($). Equipment, labour, permitting and, where eligible, storage.
- Credit rate (%). Enter your own figure; the page starts at 30%.
- Your tax liability this year ($). Enter your own figure; the page starts at $4,200.
- State or utility rebate ($). Enter your own figure; the page starts at $0.
- State tax credit rate (%). Enter your own figure; the page starts at 0%.
The result updates as you type, so you can try a figure, see what it does to federal credit, 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 |
|---|---|
| Eligible system cost | $21,500 |
| Credit rate | 30% |
| Your tax liability this year | $4,200 |
| State or utility rebate | $0 |
| State tax credit rate | 0% |
What comes out
| Result | Value |
|---|---|
| Federal credit main result | $6,450 |
| Usable against this year's tax | $4,200 |
| Carried to future years | $2,250 |
| All incentives together | $6,450 |
| Net cost after everything | $15,050 |
The credit is $6,450, but only $4,200 offsets this year's tax. The remaining $2,250 carries forward, which delays the benefit rather than removing it.
How sensitive the answer is
Holding everything else steady and changing only eligible system cost, this is what happens to federal credit. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Eligible system cost ($) | Federal credit |
|---|---|
| $10,750 | $3,225 |
| $16,125 | $4,838 |
| $21,500 example above | $6,450 |
| $32,250 | $9,675 |
| $43,000 | $12,900 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Eligible system cost ($)
- Equipment, labour, permitting and, where eligible, storage.
- Credit rate (%)
- A percentage, between 0 and 60, starting at 30%.
- Your tax liability this year ($)
- A money amount, starting at $4,200.
- State or utility rebate ($)
- A money amount, starting at $0.
- State tax credit rate (%)
- A percentage, between 0 and 50, starting at 0%.
What the results tell you
| Result | What it is |
|---|---|
| Federal credit | The headline result. A money figure. |
| Usable against this year's tax | A money figure. |
| Carried to future years | A money figure. |
| All incentives together | A money figure. |
| Net cost after everything | 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.
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