What you'll need
- Estimated system size (4kW–12kW+)
- Panel type preference (monocrystalline, polycrystalline, or thin-film)
- Roof or mounting type (asphalt shingle, tile, metal, or ground mount)
- Whether you want battery storage, EV charging, or an electrical panel upgrade
What you'll get
- Total installed cost range — System + racking + selected add-ons
- Cost per watt — Compare pricing across system sizes
- Estimated annual energy value — Projected yearly electricity offset
- Itemized cost breakdown — Panels, mounting, battery, EV charger, panel upgrade
What this page answers
This calculator answers what a solar system will cost, installed — enter (or estimate) your system size, panel type, and roof mounting above for a full price. Don't know your system size yet? The solar panel size calculator works that out first, from your monthly electricity usage. For the full list of solar tools — savings, payback, replacement, tax credit — see Solar Calculators.
Solar installation cost overview
These ranges reflect $2.50–$3.75 per watt before any incentives. The federal residential solar tax credit (Section 25D) has expired for expenditures made after December 31, 2025, so this calculator does not assume a federal credit applies — verify current state, local, or utility incentives with your installer or a tax professional.
Solar Installation Cost by System Size
| System Size | Installed Cost Range | Typical Home |
|---|---|---|
| 4 kW | $10,000 – $15,000 | Small home |
| 6 kW | $15,000 – $22,500 | Average home |
| 8 kW | $20,000 – $30,000 | Large home |
| 10 kW | $25,000 – $37,500 | Very large home |
| 12 kW+ | $30,000 – $45,000 | Whole-home / EV charging |
Ranges reflect $2.50–$3.75 per watt before incentives and vary by panel type and roof/mounting complexity. Does not assume any federal tax credit — the residential solar credit expired after 2025.
What's included — and what's often extra
Usually included
- Panels, racking & roof mounting
- Inverter (string or microinverters)
- Wiring, conduit & a production monitor
- System design, permits & interconnection paperwork
- Standard installation labor
Often extra
- Main electrical panel upgrade to 200A ($1,500–$4,000)
- Battery storage ($9,000–$16,000)
- EV charger circuit — see what a Level 2 install costs, and note the panel work and permit above are shared costs if you do both at once
- Ground mount, steep or multi-plane roof
- Re-roofing or tree removal before install
What moves the price
- System size. A bigger array costs more in total but less per watt — a 10kW system usually beats a 4kW on $/W.
- Panel type & efficiency. Premium monocrystalline costs more than value-tier panels but needs less roof space for the same output.
- Inverter choice. Microinverters or power optimizers add roughly $0.20–$0.40/watt over a plain string inverter.
- Roof type & complexity. Tile, steep pitches, and multi-plane roofs raise labor; ground mounts add racking and trenching.
- Electrical work. An older 100A panel often needs a $1,500–$4,000 upgrade to 200A before solar can be added.
- Local labor & permitting. Costs vary widely by state and by your permitting authority (AHJ).
Panel types & efficiency
- Monocrystalline (19–22%). The default for most homes — highest efficiency, best when roof space is limited, typically 25-year product and performance warranties.
- Polycrystalline (15–17%). Cheaper per panel but needs more roof area for the same output; increasingly rare on new installs.
- Thin-film (10–13%). Lightweight and inexpensive, but rarely used on residential roofs because it needs far more space.
Modern panels are 350–450W each and degrade about 0.5% per year, so a good panel still produces ~85–90% of its original output after 25 years.
Inverters: string, microinverter, or power optimizer
- String inverter. Cheapest option — one central unit for the whole array. A single shaded or underperforming panel drags down the entire string.
- Microinverters (e.g., Enphase). One per panel — best for shading and complex roofs, with panel-level monitoring. Costs more but maximizes production.
- Power optimizers (e.g., SolarEdge). Per-panel optimization paired with a central inverter — a middle ground on price and performance.
Incentives after the federal credit expired
The 30% federal residential solar credit (Section 25D) expired for systems placed in service after December 31, 2025, so this calculator does not assume a federal credit. What may still lower your cost:
- State income-tax credits and cash rebates
- Utility rebates and performance-based incentives
- SREC markets (New Jersey, Massachusetts, Maryland, and others)
- Net metering or net billing for the power you export
- Property-tax and sales-tax exemptions on the system
Check DSIRE (dsireusa.org) and your utility for current programs. This is not tax advice — confirm eligibility with a professional.
Pay cash, finance, or lease?
- Cash. Lowest lifetime cost and best return — you own the system and keep every incentive.
- Solar loan. Often $0 down; interest raises the total but you keep ownership and any incentives.
- Lease / PPA. Little-to-no money upfront, but the provider owns the system and keeps the incentives, so your savings are the smallest.
Questions to ask an installer & red flags
- Is the quote itemized — panels, inverter, labor, and permits — with panel wattage and model numbers?
- What's the modeled production (kWh/year), and does it account for your roof's shading and orientation?
- What are the panel, inverter, and workmanship warranties — and who honors them if the installer closes?
Red flags: high-pressure "today-only" pricing, vague "eliminate your bill" savings claims, or any quote that still advertises a 30% federal tax credit for a 2026 install.
Solar will not keep your lights on in an outage
This surprises most people: a grid-tied solar array without battery storage shuts itself down when the grid goes down, deliberately, so it cannot backfeed the line while a utility crew is working on it. If backup power during outages is what you actually want, the standby generator cost calculator prices the direct alternative — machine, transfer switch, wiring and gas run as separate line items — and it is worth pricing before you add storage to a solar quote for the same reason.
A new residential system prices at $2.50–$3.75 per watt before any add-ons, adjusted for panel type and roof/mounting difficulty. A 6 kW polycrystalline system on a tile roof, for example, prices at roughly $16,100–$24,200 for the array alone — tile's steeper flashing work adds about 22% over asphalt. Battery storage, an EV charger circuit, and a panel upgrade are priced separately on top.
How the price builds, in order
This calculator starts from a base cost of $2.50–$3.75 per watt for the system size you pick (4–12 kW), then multiplies twice: once for panel type — monocrystalline at 1.0×, polycrystalline at 0.88×, thin-film at 0.82× — and once for roof or mounting type, where asphalt is the 1.0× baseline, metal adds 5%, ground-mount adds 18%, and tile adds the most at 22%, reflecting the extra flashing and tile-hook labor a tile roof requires.
Estimated annual production is a flat national-average assumption of 1,300 kWh per installed kW — a 6 kW system produces about 7,800 kWh a year, which this tool values at a blended $0.16/kWh retail rate (±15% for regional variation) to estimate the electricity it offsets, not to promise actual utility savings.
No federal credit is built into this number
Every total on this page is pre-incentive. The federal residential credit that used to return 30% of a system's cost, Section 25D, is not available for property placed in service after December 31, 2025, so a 2026 installation does not get to subtract anything federal from the figures above. Use the federal solar tax credit calculator to check whether a state, local, or utility incentive still applies in your area, and layer that on separately.
Methodology
Base rate, panel-type and roof-type multipliers, and add-on ranges (battery, EV charger circuit, panel upgrade) are the literal constants in this calculator's own module. Production is a flat 1,300 kWh/kW/year national-average assumption valued at a blended $0.16/kWh. The federal-credit exclusion follows the IRS residential credit expiry below.
Sources
- IRS — Residential Clean Energy Credit (Section 25D) — accessed 2026-09-05
Frequently asked questions
How much do solar panels cost to install?
A new residential solar installation typically costs $2.50–$3.75 per watt before any incentives. A common 6 kW system runs $15,000–$22,500, while a large 10 kW system runs $25,000–$37,500. Panel type, roof/mounting complexity, and add-ons like battery storage all shift the total.
How many solar panels do I need?
Most residential panels are rated around 350–450 watts, so a typical 6 kW system needs roughly 14–17 panels, and a 10 kW system needs roughly 23–29 panels. Your exact panel count depends on panel wattage, roof space, and your household's energy usage.
Is there still a federal tax credit for solar panels?
No. The federal residential solar tax credit (Section 25D, the Residential Clean Energy Credit) that offered 30% back on solar costs has expired — it does not apply to expenditures made after December 31, 2025. This calculator does not assume any federal credit. Check with your installer or a tax professional about state, local, or utility incentive programs that may still be available in your area.
How long do solar panels last?
Solar panels are typically warrantied for 25 years and continue producing power well beyond that, usually degrading about 0.5% per year. Inverters generally need replacement after 10–15 years (string inverters) or have longer-lived microinverters, well before the panels themselves wear out.
Is solar worth it without the tax credit?
It can still be worth it, but the payback period is longer without the federal credit. Savings depend heavily on your local electricity rates, sun exposure, system cost, and any remaining state or utility incentives. Run the numbers with a local installer and compare your estimated annual energy offset against the installed cost before deciding.
What size solar system do I need for my home?
Most homes fall in the 4 kW–10 kW range depending on household energy usage, roof space, and sun exposure. A small home may only need 4 kW, an average home typically uses around 6 kW, and homes with a pool, EV charging, or high usage often need 10 kW or more. A recent utility bill and a site assessment from an installer will give the most accurate sizing.