Solar Panel Cost Calculator
Estimate what a solar system costs before and after the 30% federal tax credit, and how fast it pays back — instantly, with no address lookup or email.
What your result means
Net cost is the system price after the 30% federal tax credit, which is what you'll actually finance or pay. Gross cost is the price before the credit. Payback is your net cost divided by your yearly electricity savings. Not sure how big a system you need? Start with our PV calculator, then estimate financing with the solar loan calculator.
How to use this calculator
- Enter your system size in kW (use the PV calculator if you don't know it).
- Enter the installed price per watt — $2.50 to $3.50 is typical.
- Enter your average monthly electric bill to estimate payback.
- Read the gross cost, the net cost after the 30% credit, and the payback period.
- Subtract any state or utility rebates on top of the federal credit.
The formula
Solar is priced per watt, so a kW system times 1,000 watts times your price-per-watt gives the gross cost. The federal tax credit currently removes 30%. Payback divides the net cost by the electricity you'd no longer buy.
Worked example
An 8 kW system at $3.00 a watt is 8,000 watts times $3.00, or $24,000 gross. The 30% federal credit cuts that to about $16,800 net. If your bill is $150 a month, that's $1,800 a year in savings, so payback lands near 9.3 years.
Solar cost benchmarks (before incentives)
| System size | Typical gross cost | Roughly powers |
|---|---|---|
| 6 kW | $15,000 - $21,000 | Small/efficient home |
| 8 kW | $20,000 - $28,000 | Average home |
| 10 kW | $25,000 - $35,000 | Larger home |
| 12 kW | $30,000 - $42,000 | Large / high usage |
| Federal credit | -30% | Applies to total system cost |
Tips & gotchas
- The 30% federal tax credit applies to the whole system, including batteries — don't leave it out of your math.
- Stack state and utility rebates on top of the federal credit where available.
- Price per watt drops as system size grows — bigger systems are cheaper per watt.
- Cash payback is slower than loan cashflow; a loan can be cashflow-positive from day one.
- This is a planning estimate. A site proposal accounts for roof, shading, and net metering.
Frequently asked questions
How much do solar panels cost?
A quality home system runs about $2.50 to $3.50 per watt installed before incentives. An 8 kW system is roughly $24,000 gross, or about $16,800 after the 30% federal tax credit.
What is the 30% solar tax credit?
The federal residential clean energy credit currently returns 30% of your system cost as a tax credit, including panels, labor, and batteries. Confirm current rules for your tax year.
How long until solar pays for itself?
Most homes see payback in the high single digits to low teens of years, depending on system cost, electricity rates, and how much of your bill the system offsets.
Does this require my address or email?
No. The estimate is instant from the numbers you enter — no address lookup, no quote form, and no email signup.
Is the estimate accurate enough to buy from?
It's a planning estimate, ideal for budgeting and checking quotes. A licensed installer's proposal factors in your roof, shading, and utility's net-metering policy.
Related calculators
Estimates only — see our full disclaimer.