How many solar panels for a 1,500 square foot house?
Floor area is a proxy, not a meter. This page is for a 1,500 sq ft home, not a 1,500 kWh monthly bill. We assume 800 kWh a month for a typical home this size (gas heat, normal AC), which lands at 19 panels of 400W (7.6 kW) under average US sun. Homes this size honestly swing from about 600 kWh (15 panels) to 1,100 kWh (27 panels). If you already have bills, skip this page and use the calculator or the matching 750 kWh per month page; if you are sizing a house you have not moved into yet, stay here and read the band.
Usage variance at 1,500 sq ft
This is the table house-size searches actually need: three usage bands for the same footprint, each turned into 400W panel counts at desert, average, and cloudy sun. The middle row is this page's planning figure.
| Usage band for this size | Monthly kWh | Panels @ 4.5 h | @ 6.5 h desert | @ 4.0 h cloudy |
|---|---|---|---|---|
| Efficient (gas heat, careful use) | 600 kWh/mo | 15 | 10 | 17 |
| Typical (this page's assumption) | 800 kWh/mo | 19 | 14 | 22 |
| Heavy (all-electric or big AC/EV loads) | 1,100 kWh/mo | 27 | 19 | 30 |
Sun alone, at the typical 800 kWh assumption, moves the count from 14 panels in the desert Southwest to 22 in the cloudiest states. Pick your state in the tool; or start from the peak sun hours by state table if you only have a location so far.
Why 800 kWh for this size
The classic three-bed ranch. Quotes for this footprint often land near 16 panels / 6.6 kW when the installer assumes ~800 kWh; our table makes that kWh and the sun figure explicit so you can see which half of the quote is geometry and which half is weather.
The ranch has one advantage no other size on this list shares: it is all on one floor, so the roof footprint and the floor area are the same number. 19 panels need roughly 399 sq ft of usable roof against about 1,500 sq ft of gross footprint, before pitch, vents, code setbacks and the north face take their cut. A two-story house with the same 1,500 sq ft of living space has half that to work with, and usually a more complicated shape on top of it. If an array fits easily anywhere, it fits here.
If your bill differs, re-run the count at the real number rather than averaging floor plans. Rough rule after the 0.77 derate: about two 400W panels per extra 100 kWh/mo at 4.5 peak sun hours. Worked bill tiers live on the 750 kWh page and the situations hub.
Questions people ask
How many solar panels does a 1,500 sq ft house need?
About 19 400-watt panels (7.6 kW) at average US sun if the home uses about 800 kWh a month, our typical figure for this size. Efficient homes at ~600 kWh need about 15 panels; heavy-use homes at ~1,100 kWh need about 27. Square feet are a proxy. Twelve months of bills beat any floor-area table.
How much electricity does a 1,500 sq ft house use?
We plan on 800 kWh a month as typical, with a working band of about 600 to 1,100 depending on heat fuel, AC, and lifestyle. The midpoint is scaled from EIA's ~900 kWh national household average with usage growing slower than floor area. All-electric resistance heat can blow past the high end in winter climates.
What if my bill is different from the assumption?
Use the real number. Drop your monthly kWh into the main calculator, or open the nearest bill page (750 kWh/mo) if you want a fixed-usage walkthrough. Every extra 100 kWh a month is roughly two 400W panels at average US sun after the 0.77 derate.
Will the panels fit on the roof?
19 panels want about 399 sq ft of usable, unshaded roof once racking gaps are counted, and a 1,500 sq ft single-story home has roughly its footprint in gross roof, less pitch effects, vents, setbacks, and the north face. Usually yes on a simple gable, tight on complex roofs. Two-story homes have half the footprint to work with.
Will the panels fit on a 1,500 sq ft ranch?
Usually with room left over, and this is the easiest footprint on the list for it. A single story means the roof footprint and the floor area are the same number, so 19 panels needing about 399 sq ft are working against roughly 1,500 sq ft gross, before pitch, vents, setbacks and the north face take their share. A two-story house with the same living area has half that.