How This Calculator Works
The math is simple, and we'll show you all of it. First, we turn your monthly bill into power use. Businesses pay about $0.15 per kilowatt-hour (kWh) on average. So a $1,500 bill means you use about 10,000 kWh per month.
Next, we size a system to cover the share of your bill you picked. Sunnier states need fewer panels for the same power. Then we price it at $3.00 per watt installed — the middle of the real US range of $2.50 to $3.50.
Last, we subtract the 30% federal tax credit. That gives you the "cost after tax credit" number. Your yearly savings is simply the part of your bill that solar now covers.
What's Not in These Numbers (Good News)
This calculator is built to be careful, not hyped. A few things make your real deal even better:
- Depreciation is not included. Businesses can write off the system over 5 years (MACRS). That usually saves another 20–25% of the cost in taxes.
- State incentives are not included. Many states add their own tax credits, rebates, and property tax breaks on top.
- Rate hikes are not included. We assume power prices stay flat for 25 years. They won't. Every rate hike makes your savings bigger.
In short: if the calculator says solar works for you, the real numbers are usually better.
A Quick Example
Say you run a restaurant with a $1,500 monthly bill in an average-sun state, and you want to cover 70% of your power:
- System size: about 58 kW
- Cost before incentives: about $174,000
- 30% tax credit: about −$52,000
- Cost after credit: about $122,000
- Savings per year: about $12,600
- Payback: under 10 years — and usually 4–7 years once depreciation and state perks are added
After payback, that's roughly $12,600 a year in saved power costs, every year, for the rest of the system's 25+ year life.
What Changes Your Real Price
Five things move a real quote up or down from this estimate:
- Your roof. Flat roofs in good shape are cheapest. Old roofs may need work first.
- Your local power rate. If you pay more than $0.15 per kWh, your savings are bigger than shown. Cheaper power means smaller savings.
- Your sun hours. The same panels make more power in Phoenix than in Seattle.
- Your equipment choice. Premium panels and inverters cost more but produce more and last longer.
- Local permits and labor. Costs vary by city and state.
From Estimate to Exact Quote
This calculator answers one question: "Is solar worth a closer look for my business?" If your numbers look good, the next step takes 60 seconds. We match you with up to three licensed, insured installers in your state. They review your real bills and your real roof, then give you exact prices to compare. It's free, and there's no pressure to buy.
One more reason to move now: the 30% federal tax credit requires construction to start by July 4, 2026 — only weeks away. Our tax incentives guide explains how the deadline works, and why a small deposit can still lock in your credit.
Calculator Questions
How accurate is this solar cost calculator?
It gives you a solid ballpark, not an exact price. We use real industry averages: about $3.00 per watt installed and $0.15 per kWh for business power. Your real quote depends on your roof, your local rates, and your power use. Most real quotes land within 20% of this estimate.
Does the calculator include the 30% federal tax credit?
Yes. The "cost after tax credit" number already subtracts the 30% federal Investment Tax Credit. It does not include MACRS depreciation, which usually saves businesses another 20-25%. So your real net cost is often even lower than the number shown.
What monthly bill makes solar worth it for a business?
Solar starts making sense at around $500 per month. The bigger your bill, the better the math. Businesses paying $1,500 or more per month usually see payback in 4-7 years, then nearly free power for 20 more.
Why is my real quote different from the calculator?
A real quote uses your exact power bills, your roof size and direction, your local sun hours, and your state incentives. The calculator cannot see those details. That is why the smart next step is a free custom quote from licensed installers.
Like What the Calculator Shows?
Get your exact numbers from licensed installers in your state. Free, fast, and zero pressure — and the tax credit deadline is only weeks away.
Get My Free Solar QuoteA quick note: all calculator results are estimates for education only. They are not a quote, a guarantee, or tax advice. Your real costs and savings depend on your location, roof, power use, and current incentive rules. Always confirm tax credit details with a tax professional.