Planning with U.S. state data and USD. Translations do not change the market or currency.
No email. No phone gate. Just the estimate first.
Estimate your solar system size, panel count, roof space, cost, savings, and payback in under a minute.
Start here for a fast, contact-free planning estimate; use the dedicated calculators when panel count, cost, or payback is your main question.
Electricity rates checked October 25, 2026; other assumptions have separate review dates. See sources and update cadence.
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Enter monthly kWh or electric bill. The calculator uses state-level assumptions and shows the math behind the result.
Your estimate
Example resultEstimated system size: 6.8 kW. This is an estimate, not an installer quote.
Confidence
Medium
Planning estimate only — not an installer quote, engineering design, or tax advice.
Payback uses gross system cost before verified incentives, financing fees, batteries, and roof work.
Annual usage: 10,800 kWh
Annual production target: 10,800 kWh
State rate: 29.75 cents/kWh
Export assumption: Partial export credit
Direct solar use: 5,940 kWh
Modeled exports: 4,860 kWh
Panel count view
15-19 panels
Estimate shape
Privacy note: the printable report link stores estimate inputs in the URL, including ZIP and usage or bill values. Keep it private if those details are sensitive.
Review one assumption at a time. Each tool explains its inputs and limits; a planning result is not a roof design or installer quote.
Monthly shape comes from the PVWatts AC reference model, scaled to this annual estimate. Losses are already included. This is a seasonal planning illustration, not a roof or ZIP model. Monthly balances do not measure imports, exports or bill credits; those need interval matching and tariff rules.
Consumption repeats the entered monthly average. Enter 12 months above to see seasonal demand.
| Month | Usage | Production | Production − usage | |
|---|---|---|---|---|
| Jan | 900 | 575 | -325 | |
| Feb | 900 | 644 | -256 | |
| Mar | 900 | 910 | +10 | |
| Apr | 900 | 996 | +96 | |
| May | 900 | 1,111 | +211 | |
| Jun | 900 | 1,142 | +242 | |
| Jul | 900 | 1,187 | +287 | |
| Aug | 900 | 1,124 | +224 | |
| Sep | 900 | 1,031 | +131 | |
| Oct | 900 | 868 | -32 | |
| Nov | 900 | 667 | -233 | |
| Dec | 900 | 545 | -355 | |
| Annual usage | 10,800 | 10,800 | 0 |
Local scenarios
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Saved scenarios stay in this browser only and may include ZIP, bill, and usage inputs. SolarCalcNow does not sync them or send those values to analytics.
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Confidence drivers
Expected production: 10,800 kWh
System loss: 14%
Export value: Partial export credit
Direct solar use: 5,940 kWh
Modeled exports: 4,860 kWh
State production default: 1,595 kWh/kW/year
EIA Electric Power Monthly, Table 5.6.A — August 2026 - 2026-10-25
NLR PVWatts V8 · author-selected reference point - 2026-11-02
EnergySage marketplace + SolarCalcNow cost scenario - 2026-10-25
Production evidence: full PVWatts responses were retained for 10 reference points on November 2, 2026. Illinois and Pennsylvania still use the disclosed authored assumptions; the provider quota prevented their verification. Each input retains its own source and review date.
$0.2975/kWh
29.75 ¢/kWh
EIA Table 5.6.A, August 2026 residential column; published October 23, 2026. Divide the published cents/kWh by 100. This preliminary statewide average is a fallback, not your utility tariff. Use your bill's energy-only rate; fixed charges remain payable.
1,595.2 kWh/kW/year
kWh/kW/year
PVWatts V8 typical-weather model at an author-selected reference point in the state: 4 kW DC, roof mount, 20° tilt, 180° azimuth, 14% system losses. Annual AC kWh ÷ 4 gives kWh/kW/year. Losses are already included and are not deducted again. Neither a statewide average nor a ZIP or roof survey. Shade and ±10% production bounds are separate author scenarios.
$2.02–$3.02/W
$2.52/W × 0.8…1.2
EnergySage's state marketplace average, table retrieved October 25, 2026; individual quote dates are not supplied. We calculate an author-selected range of average × 0.8 to average × 1.2, rounded to cents/W. This ±20% scenario is not an observed price distribution or confidence interval. Cash solar only, before incentives; compare like-for-like local quotes.
SolarCalcNow provides planning estimates only. Results are not installer quotes, engineering designs, tax advice, financing recommendations, or utility interconnection approval.
Optional next step
Your estimate stays visible. This form is optional and uses explicit consent.
Installer quote matching is not active yet. You can still calculate, save, and print your estimate before contacting installers directly.
Transparent formulas
SolarCalcNow starts from monthly usage or bill, state electricity rate, state production assumption, panel wattage, shade, and target offset. It shows a confidence level instead of pretending every home can be estimated perfectly.
Gross cost is shown before incentives. Verified state and local incentives can be added later, but they should never be silently hardcoded into payback without source review.
See the methodologyState calculators
FAQ
It is a planning estimate, not an installer quote. Shade, roof orientation, utility rules, equipment, financing, permitting, and installer pricing can change the final result.
Monthly kWh is best. If you only know your monthly bill, the calculator estimates usage from the selected state's residential electricity rate.
The calculator shows gross cost first and does not apply incentives by default. Incentives change quickly and need source, updated date, eligibility, and active status before being used in net-cost math.
Panel count depends on panel wattage, roof layout, shading, design setbacks, and installer equipment choices. A range is more honest than a single guaranteed number.
Yes. South-facing roofs with low shade usually produce more than east/west roofs or heavily shaded sections. SolarCalcNow uses a simple shade level, not a site-specific layout or LIDAR model.
State electricity rates and production assumptions are reviewed on a published cadence, and every figure links back to its source with the date it was last checked. Utility rates and net-metering rules can still change between reviews, so confirm current terms with your utility before signing anything.