Solar calculator · 2026

How much will solar actually save you?

Pick your city and enter your monthly electric bill. We'll size a system, apply your state's real incentives, and show your honest payback period — using NREL PVWatts data and EIA retail rates, not industry-average guesses.

We currently support 25 cities across CA, TX, FL, AZ, NY. More launching weekly. Your data isn't saved or shared.

Same bill, four cities — wildly different math

What a $200/month electric bill means in four metros. Notice how net-metering policy and state incentives matter as much as how sunny it is.

Phoenix, AZ

7.2 yrs

payback period

Net cost
$15,763
25-yr savings
$63,681

San Francisco, CA

6.1 yrs

payback period

Net cost
$11,426
25-yr savings
$65,801

Buffalo, NY

4.9 yrs

payback period

Net cost
$11,793
25-yr savings
$75,509

Miami, FL

7.5 yrs

payback period

Net cost
$17,929
25-yr savings
$63,890

How the math works

  1. 1

    Convert your bill into kilowatt-hours

    We divide your annual electric spend by your state's average residential retail rate (EIA). That gives us the kWh your system needs to offset.

  2. 2

    Size the system using local sun data

    NREL PVWatts tells us how many kWh a 1 kW system produces annually at your specific latitude/longitude. We size to cover 100% of your usage.

  3. 3

    Apply incentives in the right order

    Sales-tax exemptions reduce the upfront cost. Upfront rebates reduce the cost basis. Then federal (30%) and state tax credits apply to that basis.

  4. 4

    Project 25 years honestly

    Year-1 savings derate exports by your state's net-metering rule. Long-term savings include 0.5%/year panel degradation and your state's typical retail-rate inflation.

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Common questions

How accurate is this solar calculator?

Our production estimates come straight from NREL PVWatts v8 — the same dataset major installers use. Retail electric rates are state-level averages from EIA. We model federal and state incentives explicitly. The biggest source of variance is your individual installer quote and roof condition; expect actual quotes within ±15% of our gross estimate.

What's the average solar payback period in 2026?

For our 5 launch states the typical residential payback ranges from about 4–5 years (New York, due to stacked state credits and rebates) to 7–8 years (Arizona, despite high production, because retail rates are lower). Most US homeowners see 6–10 years.

Does this calculator include the federal solar tax credit?

Yes — we apply the 30% Residential Clean Energy Credit (Inflation Reduction Act) to your post-rebate cost basis. The credit steps down to 26% in 2033 and 22% in 2034 under current law.

Why is California's payback longer than I expected?

California adopted NEM 3.0 in April 2023, which compensates exported solar energy at avoided-cost rates roughly 75% lower than retail. We model this explicitly. Solar still pays back in 6–8 years in most CA cities, but it pencils much better when paired with a battery — something we'll add to the calculator soon.

How is system size calculated?

We size your system to offset 100% of your annual electricity usage based on your monthly bill, your state's average retail rate, and the local annual production at your zip. You can override this in v2.

What if I'm not in California, Texas, Florida, Arizona, or New York?

Those are our launch states — we picked them because they cover ~60% of US residential solar installations. We're adding states each month. Subscribe to PanelMath updates from the homepage and we'll email when your state launches.

Are there hidden affiliate links or installer kickbacks?

Not yet. When we add installer-quote partners later, every link will be disclosed and the calculator math will be unaffected. Numbers we publish are the numbers we'd use ourselves.