How Many Solar Panels Do You Need? The Quick Answer for 2026

You want to go solar. The first question everyone asks is how many panels you need.

The answer depends on three things: your electricity usage, your roof space, and your location.

Here is how to figure it out in under two minutes.

Step 1: Check your electricity usage

Look at your last electric bill. Find your monthly usage in kilowatt-hours (kWh). The national average is about 900 kWh per month. In hot climates like Texas, Arizona, and Florida, it is closer to 1,200 to 1,500 kWh per month.

Write that number down.

Step 2: Know your panel output

A standard residential solar panel produces about 350 to 400 watts. In a sunny location, one panel generates roughly 1.5 kWh per day, or about 45 kWh per month.

Step 3: Do the math

Divide your monthly usage by the monthly output per panel.

Example: If you use 1,200 kWh per month and each panel produces 45 kWh per month:

1,200 divided by 45 equals 27 panels.

That is a rough estimate. Your actual number will vary based on shade, roof orientation, and local weather patterns.

Typical system sizes by home

| Home size | Monthly usage | Estimated panels | System size | |---|---|---|---| | Small (1-2 bedrooms) | 600-800 kWh | 14-18 | 5-7 kW | | Medium (3-4 bedrooms) | 900-1,200 kWh | 20-27 | 7-10 kW | | Large (5+ bedrooms) | 1,200-1,800 kWh | 27-40 | 10-16 kW |

Does roof space matter?

Yes. Each panel takes up about 17 to 20 square feet. A 27-panel system needs roughly 500 square feet of unobstructed roof space.

If your roof is small, shaded, or has many obstructions, you may not be able to fit the ideal number of panels. Higher-efficiency panels (400+ watts) take up less space but cost more.

The fastest way to get your exact number

You can estimate using the math above. But estimates are not accurate. Shade, roof angle, orientation, and local weather all change the real output.

SolrScan gives you a satellite-powered roof analysis in 60 seconds for $19. It tells you exactly how many panels fit on your roof, how much shade you have, and how much energy you can realistically produce.

Get your SolrScan report for $19

Bottom line

Most homes need 20 to 30 panels. But your roof might not support that many. Check your roof first before you commit to a system size.

Get your SolrScan report for $19