Solar Savings Calculator 2026: Estimate Your Payback in 60 Seconds
Short answer: this solar savings calculator estimates your rooftop solar payback in about a minute. Enter your monthly electricity bill, your rate, sunlight quality, and installed cost per watt, and it estimates your annual usage, recommended system size, gross and net cost, year-one savings, simple payback period, and 25-year savings – using honest 2026 numbers, including the end of the federal solar tax credit.
The calculator
Your estimate
| Estimated annual electricity use | |
|---|---|
| Recommended system size | |
| Gross system cost | |
| Federal tax credit (2026, owned system) | |
| State/local incentive | |
| Net cost after incentives | |
| Estimated year-1 savings | |
| Simple payback period | |
| Estimated 25-year savings |
Estimates only, not financial advice. Get quotes from licensed installers before deciding. This math assumes your system offsets your full bill and ignores rate inflation, panel degradation, and maintenance.
How the math works
The calculator uses simple labeled formulas, not black-box magic. Here is exactly what it does:
The 0.8 derate factor accounts for real-world losses: inverter efficiency, wiring, dust, and heat. Gross cost is system watts times your cost-per-watt. Net cost subtracts the federal credit (0% for 2026 owned systems) and any state incentive you enter. Year-1 savings equals your current annual bill, since the system is sized to cover your full usage. Simple payback is net cost divided by year-1 savings. 25-year savings is year-1 savings times 25 minus net cost.
The 2026 tax-credit reality
Solar still works in 2026, but the math changed. The 30% federal residential credit (Section 25D) ended December 31, 2025 under the One Big Beautiful Bill Act, signed July 4, 2025. If you own your system outright, your federal credit is 0%. That is baked into the calculator above, so you will not see inflated savings based on a credit you cannot claim.
There are still paths worth checking. Leased systems and power-purchase agreements can still use the commercial clean electricity credit (Section 48E), so a lease quote may look better than ownership in 2026. State and utility incentives did not disappear with the federal credit – some states still offer rebates, property tax exemptions, or net-metering that shortens payback meaningfully. Sources: NRG Clean Power’s federal solar tax credit updates and GovtSchemes’ 2026 explainer.
Frequently asked questions
Does solar still pay for itself without the federal credit?
Often yes, but the payback period gets longer. The calculator shows you the unvarnished number. High electricity rates and strong sunlight shorten payback the most; expensive installations in cloudy regions are the hardest case. That is exactly why the cost-per-watt and sunlight inputs matter.
Lease vs buy now – which is better in 2026?
Ownership lost its biggest perk: the 30% credit. Leases and PPAs can still tap the commercial credit (Section 48E), which the installer may pass through as a lower monthly payment. If a lease quote plus 25 years of payments beats owning with zero federal credit, the lease can win – run both through this calculator’s payback logic and compare.
How accurate is this solar savings calculator?
It is a solid ballpark, not a quote. It uses your bill, your rate, your sunlight estimate, and 2026 cost benchmarks ($2.50-$3.30/watt per EnergySage/NREL). It ignores roof angle, shading, net-metering rules, panel degradation, and rising electricity rates. Treat it as a first filter: if payback looks good here, get three licensed installer quotes to confirm.
What system size does the average home need?
It depends on the bill, not the house. At the defaults (a $150/month bill, $0.17/kWh, average sunlight), the calculator estimates about 10,600 kWh a year and roughly a 9 kW system. Bigger bills mean bigger systems – the math scales directly.
Keep cutting your energy bills
Solar is one piece of a lower-bill home. Our guide to heat pump cooling for a 2,160 sq ft home covers another major electricity driver, and home insulation savings shows how sealing the envelope shrinks the load your solar system has to cover.
Last updated September 28, 2026. Tax rules change; verify current federal and state incentives with a tax professional. Sources for the facts used here: NRG Clean Power – Federal Solar Tax Credit Updates, GovtSchemes – Federal Solar Tax Credit 2026, Sunhub – Solar Panel Price Per Watt.
How to use this solar savings calculator
Start with the bill and rate from your latest utility statement, choose the sunlight quality that matches your roof, and enter the installed cost per watt from a local quote (or keep the $2.85 default). Click “Calculate my savings” and this solar savings calculator estimates your annual usage, recommended system size, gross and net cost, year-one savings, simple payback period, and 25-year savings.
Because this solar savings calculator uses honest 2026 math – a 0% federal credit for homeowner-owned systems – its payback figure already reflects the post-credit world instead of the old 30% era. If a lease quote looks cheaper, run both scenarios through the solar savings calculator: leased systems can still use the commercial credit, so comparing owned vs. leased payback in a single solar savings calculator session shows which path pays off first.
Bookmark this solar savings calculator and rerun it whenever your utility rate changes or a new installer quote arrives – a higher rate or a lower cost per watt shortens payback fast, and this solar savings calculator makes the comparison instant. If the solar savings calculator shows a payback under 10 years at your numbers, it is worth getting three licensed installer quotes – that is exactly what this solar savings calculator is for.
