Solar Panel Savings Calculator

Enter your average monthly electric bill, your system cost after incentives, and the share of your usage the panels will cover. The calculator instantly shows your estimated annual savings, simple payback period, and 25-year savings — all in your browser, nothing uploaded.

📖 How it works & FAQ

Average monthly electric bill ($)

System cost after incentives ($)

Usage offset by solar (%)

Assumed utility rate increase (%/yr)

What this solar savings estimate shows

The calculator turns three numbers you already know into the three numbers every solar quote conversation comes down to. Annual savings is your monthly bill multiplied by 12, then by the share of usage your panels offset. Simple payback is your net system cost divided by that annual savings — the years until the panels have paid for themselves. The 25-year figure is annual savings times 25 (a typical panel warranty life) minus the system cost, so it represents total money kept over the system's expected lifetime.

Because utility rates rarely stay flat, the rate-increase field lets you see a second, usually more realistic 25-year number that compounds your savings as electricity prices climb. Every assumption is editable, and the results update live as you type. These figures are rough estimates only — not professional, financial, or tax advice. Get itemized quotes and a production estimate for your actual roof before signing anything.

How to use it

Enter your average monthly electric bill. Averaging 12 months of bills smooths out summer and winter swings.
Enter the system cost after incentives — the installer's price minus tax credits, rebates, and any utility incentives.
Set the percentage of your usage the system will offset. Your installer's production estimate usually states this; 80–100% is common.
Adjust the assumed utility rate increase if you like, then read the three result cards. Nothing is saved or sent anywhere.

FAQ

What counts as "system cost after incentives"?: The out-of-pocket price once the federal solar tax credit and any state or utility rebates are subtracted. If you finance, you can still use the cash price here and treat loan interest as an extra cost to weigh separately.
What offset percentage should I use?: Use the installer's estimate of production divided by your annual usage. Shaded roofs or small systems may only offset 50–70%; a well-sized system in a sunny area often reaches 90–100%.
Is the 25-year number realistic?: It is a simplified estimate. Rising rates push real savings higher, while panel degradation (roughly 0.5% per year) and a possible inverter replacement pull them lower. The flat and rate-increase figures bracket a reasonable range.
Is my information private?: Yes. Everything runs in your browser with plain JavaScript — no accounts, no uploads, and nothing leaves your device.