Solar Panel Cost Calculator

What drives installed cost per watt

Hardware is a smaller share of a residential solar bill than most people expect. Panels, inverters, and racking together typically make up well under half of the installed price. The rest is labor and what the industry calls soft costs, and those vary far more from one market to another than the equipment does.

• Equipment. Standard monocrystalline panels with a string inverter are the baseline. Premium panels, microinverters, or power optimizers add roughly $0.25–$0.75 per watt but can be worth it on shaded or multi-plane roofs.
• Labor. A crew of three or four spends one to three days on a typical roof. Electrician and roofer wages differ by a factor of two between low-cost and high-cost states, which is the main reason regional prices diverge.
• Permitting and interconnection. Building permits, electrical inspections, engineering stamps, and the utility interconnection application. Some jurisdictions charge a few hundred dollars; others take months and cost several thousand in fees and staff time.
• Sales and overhead. Customer acquisition, design, project management, insurance, and margin. This is the largest soft cost and the one most open to negotiation.
• Roof type. Asphalt shingle is cheapest to work on. Clay or concrete tile, standing-seam metal, and slate need special mounts and slower installation. Steep pitches and many small roof planes add hours per job.

Typical 2026 price per watt by region

Our cost by state comparison groups states into three tiers based on labor rates, permitting burden, and market maturity. The figures are modeled averages for a cash purchase, not surveyed prices, and a real quote can land $0.30–$0.50 on either side of them.

• Low-cost tier, about $2.70/W: Texas, Florida, Arizona, Nevada, New Mexico, Georgia, the Carolinas, Oklahoma, Louisiana, Tennessee, and most of the Deep South. Competitive installer markets and lower wages keep prices down.
• Mid-cost tier, about $3.00/W: most of the Midwest, Mountain West, and Pacific Northwest, plus Virginia, Pennsylvania, Delaware, and Colorado.
• High-cost tier, about $3.35/W: California, New York, New Jersey, Massachusetts, Connecticut, Rhode Island, Maryland, northern New England, Alaska, and Hawaii. High rates in these states usually make up for the higher price at payback time.

Cost by system size and price tier

Gross cost is size × 1,000 × price per watt; net cost subtracts the 30% federal credit. Sizes of 6 to 12 kW cover the large majority of US homes.

Net figures assume you can use the full federal credit. Batteries and add-ons are extra.

How to compare quotes

Quotes for the same house rarely propose the same system size, so the total price alone tells you little. Divide the cash price by the system size in watts to get price per watt, and compare that. A $26,400 quote for 24 panels at 400 W is a 9,600 W system at $2.75/W; a $22,000 quote for 18 of the same panels is 7,200 W at $3.06/W and is the more expensive offer per watt despite the lower total.

Ask each installer for the cash price even if you intend to finance. Solar loans often carry dealer fees of 10–30% that are built into the financed system price, which inflates the apparent price per watt and shrinks your federal credit relative to what you actually pay in cash. The cash vs. loan vs. lease comparator shows how those fees change the lifetime cost.

Common add-ons outside the price per watt

• Battery storage. The calculator’s battery option adds about $9,000 for a small backup unit or $18,000 for whole-home storage. Batteries qualify for the same 30% federal credit. Size one with the solar battery calculator.
• Main panel upgrade. Homes with a 100 A service panel or no spare breaker space often need a 200 A upgrade, commonly $2,000–$4,000 and more where the utility has to replace the service drop.
• Roof work. If your roof has fewer than ten years of life left, re-roofing before the install avoids paying to remove and reinstall the array later. Partial re-roofing under the array footprint is a cheaper middle option.
• Site work. Tree trimming, trenching for a ground mount, or a long conduit run to a detached garage are billed separately.

Incentives beyond the federal credit

The calculator applies only the 30% federal Residential Clean Energy Credit, which you can check in detail with the federal tax credit calculator. Many states and utilities layer more on top, and each one lowers your net cost further.

• State tax credits in states such as New York, South Carolina, and Arizona, typically capped at a few thousand dollars.
• Upfront rebates from utilities or state programs, paid per watt installed or as a flat amount.
• Solar renewable energy certificates (SRECs) or performance payments in New Jersey, Massachusetts, Illinois, and a few other states, paid over time rather than at purchase.
• Property and sales tax exemptions, which do not change the quote but remove costs you would otherwise pay.

As an example, a $24,000 system with a $7,200 federal credit and a $1,000 state rebate nets out at $15,800 rather than $16,800. Utility rebates can reduce the cost basis on which the federal credit is calculated, while state tax credits generally do not, so confirm the order of operations with a tax professional before counting on a specific figure.