Solar Panel Cost Calculator
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How big a solar system do you need, what will it cost, what will it save, and when does it pay for itself? Enter your electric bill — get system size, panel count, gross and net cost, annual production, savings, and payback years, with every step of the math shown. No email required.
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State rates: EIA average residential prices, May 2026. State sun hours: NREL PVWatts / NSRDB state averages. The calculator's national defaults ($0.17/kWh, 4.5 hours) predate the May 2026 EIA U.S. average ($0.1844/kWh) — pick your state for the newer figure, or type your bill's actual rate. State averages hide big local variation: your roof's sun and your utility's tariff always beat the average.
Worked example: a $150/month bill, fully itemized
Computed by the calculator above · $0.17/kWh · 4.5 peak sun hours · $2.70/W · 400 W panels · no federal credit (2026 law) · October 2026
| Line item | Math | Result |
|---|---|---|
| Annual electricity use | $150 × 12 ÷ $0.17 | 10,588 kWh |
| System size needed | 10,588 ÷ (365 × 4.5 × 0.80) | 8.1 kW |
| Panels needed | 8,100 W ÷ 400 W | 21 panels (rounded up) |
| Gross cost | 8.4 kW × $2,700/kW | $22,680 |
| Federal tax credit (2026) | §25D ended Dec 31, 2025 | $0 |
| Net cost | $22,680 | |
| Annual production | 8.4 × 4.5 × 365 × 0.80 | 11,038 kWh |
| Annual savings | 11,038 × $0.17 | $1,876 / year |
| Payback | $22,680 ÷ $1,876 | 12.1 years |
| Scenario | Net cost | Typical range (±25%) |
|---|---|---|
| No federal credit (2026 law) | $22,680 | $17,010 – $28,350 |
| With 30% credit (2025 installs only) | $15,876 | $11,907 – $19,845 |
This is exactly what the calculator above produces for these inputs — run it yourself and check. The pattern that matters: without the former federal credit, payback is driven mostly by your electricity rate and sun hours, not by the panels — which is why the region table below matters more than ever.
Where the $22,680 goes: component shares
Our worked example ($150/month bill, 8.4 kW, $22,680 gross) broken into typical component shares. These are illustrative shares applied to our own total, not a quote — your installer's mix will differ.
| Component | Share | On the $22,680 example |
|---|---|---|
| Panels | 25% | $5,670 |
| Inverter | 10% | $2,268 |
| Racking | 7% | $1,588 |
| Wiring | 6% | $1,361 |
| Labor | 30% | $6,804 |
| Permits | 3% | $680 |
| Interconnection | 2% | $454 |
| Monitoring | 2% | $454 |
| Sales, design & overhead | 15% | $3,401 |
The useful read: panels are only about a quarter of the price. Chasing a cheaper panel tier saves hundreds; negotiating the quote's structure saves thousands.
Battery storage: what it adds
Storage is excluded from the base $/W price above. Installed ranges below are competitor-reported figures (5Estimates' battery table), not our measurements — get a line-item battery price on your own quote and compare it like-for-like.
| Battery | Capacity | Installed range (reported) |
|---|---|---|
| Tesla Powerwall 3 | 13.5 kWh | $11,000–$15,000 |
| Enphase IQ 5P | 5 kWh per unit | $5,500–$7,500 per unit |
| LG Chem RESU Prime | 10–16 kWh | $9,000–$14,500 |
| FranklinWH | 13.6 kWh | $10,000–$14,000 |
A battery pays in three situations: frequent outages (backup power), time-of-use rates (store cheap power, use it at peak prices), or weak net metering (your exports earn little, so storing beats selling). Under full retail net metering, a battery is mostly a resilience purchase, not a savings purchase. Size storage to your critical loads, not to the whole panel array.
Cash vs loan vs lease: the financing trap
Cash is the cheapest way to buy solar: you pay the sticker price and own the system. A $0-down loan looks cheaper monthly but often carries dealer fees of 20–30% baked into the financed amount — one wholesaler's worked case turns a $24,000 cash system into about $31,000 financed (reported by Portlandia Electric Supply, not our data). Always ask for the cash price and the financed price side by side. A lease or PPA (power purchase agreement) means you do not own the system: you pay for the power it produces, usually with an annual escalator, and the installer keeps the incentives.
Before you sign a solar quote
- Price above $3.50/W cash — get a second quote before proceeding.
- No itemized breakdown — panels, inverter, labor, and fees should each be their own line.
- Same-day pressure — reputable installers hold quotes for 30 days.
- No panel brand or model named — "premium panels" is not a specification.
- System oversized vs your bill — most states cap net-metering credits near 100–120% of annual usage; a system far bigger than your bill only pays if you are adding an EV or heat pump.
- A good quote shows: panel model + wattage, inverter make/model, kW DC, expected annual kWh with assumptions stated, itemized pricing, equipment AND workmanship warranty terms separately, production-guarantee language, assumed utility rate + escalation, and a valid-through date.
What's included — and what isn't
✓ Included in every estimate
- Panels, inverter, racking, and wiring
- Installation labor and permitting
- State incentives you enter (the federal §25D credit ended Dec 31, 2025 — see the tax-credit FAQ below)
- Production estimate with an 80% real-world derate (heat, dust, inverter losses)
- Payback math from your actual bill and rate
✗ Not included
- Battery storage (typically $9,000–$15,000 extra)
- Main panel upgrades (often $1,500–$3,000 if needed)
- Roof replacement or major roof repair before install
- Tree removal or heavy shading mitigation
- Financing interest (cash price shown; loans add cost)
If a contractor's quote covers items on the right-hand list and ours doesn't, that's expected — ask them to itemize it before comparing.
The price data behind this calculator
Checked October 2026
Data freshness: prices verified October 2026 · next scheduled re-check January 2027. If a major price move happens sooner, we update sooner. Our update policy is public.
| Input | 2026 value | Source / note |
|---|---|---|
| Installed cost per watt | $2.50–$3.00 | US residential market range, 2026 installer quotes |
| Federal tax credit (§25D, homeowner) | 0% for 2026 installs | Ended Dec 31, 2025 (One Big Beautiful Bill Act); 30% applied only to systems placed in service by that date |
| Average electricity rate | ≈ $0.17/kWh | US residential average, 2026 |
| Typical panel wattage | 400–440 W | Current mainstream residential panels |
| System derate factor | 0.80 | Heat, soiling, inverter and wiring losses combined |
| Battery add-on | $9,000–$15,000 | Typical 10 kWh home battery, installed |
Prices move by installer, roof complexity, and state — every input above is editable in the calculator. Our full sourcing and update policy: methodology.
Solar costs by region: same system, different payback
Every competitor with a state table shows the same lesson: where you live moves payback more than panel brand. Same 8.4 kW system at $22,680 gross, no incentives — only sun hours and electricity rate change:
| Region | Peak sun hours | Typical rate | Annual production | Annual savings | Payback |
|---|---|---|---|---|---|
| Southwest (AZ, NM, NV) | 5.75 | $0.15 | 14,104 kWh | $2,116 | 10.7 years |
| Southeast (FL, GA, SC) | 4.75 | $0.14 | 11,651 kWh | $1,631 | 13.9 years |
| Midwest (OH, IL, MI) | 4.25 | $0.15 | 10,424 kWh | $1,564 | 14.5 years |
| Northeast (MA, NY, CT) | 4.00 | $0.24 | 9,811 kWh | $2,355 | 9.6 years |
| Northwest (WA, OR) | 3.75 | $0.12 | 9,198 kWh | $1,104 | 20.5 years |
Illustrative — computed with this page's own formula (production = kW × sun hours × 365 × 0.80). High-rate regions pay back fastest despite less sun; low-rate regions take longest even with decent sun. For your state's current incentives, check the DSIRE database (dsireusa.org).
How to size a system in 3 steps
- Find your annual kWh. Check 12 months of electric bills (or one bill × 12). This — not your roof size — sets the system size.
- Divide by your sun hours. Annual kWh ÷ (365 × peak sun hours × 0.80) gives the kW you need. Your state solar office or PVWatts publishes local sun-hour figures.
- Sanity-check the roof. Each 400 W panel needs about 18–20 sq ft. A 21-panel system needs roughly 400 sq ft of usable, unshaded roof facing south, east, or west.
Three ways people get solar math wrong
- Counting a federal credit that no longer exists. Quotes and calculators built before 2026 still show 30% off — for a 2026 homeowner install that discount is gone. If a quote's "net cost" subtracts a federal credit, ask which credit and whether you can actually claim it.
- Sizing by roof, not by bill. A roof that fits 30 panels doesn't mean you need 30 panels — oversizing wastes money unless net metering pays full retail for exports.
- Forgetting the derate. A 8 kW system does not produce 8 kW all day. The 0.80 factor in this calculator accounts for heat, dust, and inverter losses — quotes that skip it overpromise production by ~20%.
- Comparing gross prices. Always compare net cost after any state incentives, and always compare cost per watt — not headline totals for different-sized systems.
Net metering: why your payback depends on it
Your payback years hinge on one policy as much as on sunshine: net metering — how your utility credits you for power your panels send to the grid. Under full retail net metering, every exported kilowatt-hour offsets a kilowatt-hour you buy later, so the calculator's simple payback math holds. Under newer rules in several states, exports earn only a wholesale or avoided-cost rate (sometimes 25–40% of retail), which stretches payback by years unless you shift usage into daylight hours or add a battery. Before signing a contract, ask your installer to model your bill under your utility's current export rate, not last year's, and check whether your state is scheduled to change its net metering rules — that single number can matter more than panel brand or a $0.10/W price difference.
Solar cost FAQs
How many solar panels do I need for my home?
It depends on your electricity use, not your roof size. A home using 900 kWh per month with 4.5 peak sun hours needs about an 8.2 kW system — roughly 21 panels at 400 watts each. Enter your bill above for your exact number.
How much do solar panels cost in 2026?
About $2.50–$3.00 per watt installed, so a typical 7–8 kW system runs $17,500–$24,000 — and in 2026 that is also the net cost for homeowner-owned systems, since the former 30% federal credit ended Dec 31, 2025. State and utility incentives can still reduce it.
Is there still a 30% federal solar tax credit in 2026?
No — not for homeowner-owned systems. The Section 25D residential clean energy credit ended for systems placed in service after December 31, 2025, under the One Big Beautiful Bill Act (July 2025). A system installed in 2026 gets no federal credit, even if you signed or paid in 2025 — what counts is when installation finished. Leased and PPA systems may carry indirect value through the installer's separate commercial credit, and state and utility incentives still apply — check the DSIRE database for your state.
How long until solar panels pay for themselves?
Without the former federal credit, most US homes break even in roughly 10–16 years. High-rate states can pay back in 8–10 years; low-rate states take longer. The calculator above computes your payback from your actual bill and rate.
Do solar panels work on cloudy days or in winter?
Yes, at reduced output — roughly 10–25% of rated power under heavy cloud, and less in winter with shorter days. The peak-sun-hours figure is a yearly average, so annual estimates already include this.
Do I need a battery with solar panels?
Not necessarily. Without one, excess daytime power goes to the grid (net metering where available) and you draw from the grid at night. A battery adds $9,000–$15,000 and makes sense mainly for backup power or poor net-metering terms.
How accurate is this calculator?
It's a budgeting estimate built on 2026 price ranges — good for budgeting and sanity-checking installer bids. Every result shows a ±25% planning range because real quotes move with roof, installer, and state. See how we compute costs for the full method and limitations.