Solar Panel for Home Calculator

Enter your home size and heating type — get a recommended solar system tailored to your home.

Your home

Home size?

sq ft

Bedrooms?

Heating / cooling type?

Electricity details (optional but improves accuracy)

Monthly electricity bill?

Electricity rate?

$/kWh

Peak sun hours?

hrs/day

Panel wattage?

Recommended solar system for your home

15 panels (6.0 kW)

Est. monthly usage683 kWh

Annual production8,475 kWh

System cost (before ITC)$15,000–$21,000

After 30% tax credit$10,500–$14,700

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How to Use This Calculator

Enter your home size and bedrooms

This calculator estimates your solar needs from your home's characteristics — square footage, bedrooms, and HVAC type — rather than requiring a utility bill. It's designed for homeowners who are exploring solar before they have their bills in hand, or who want to cross-check their consumption estimate.

Select your heating and cooling type

Your HVAC system is the single largest factor in home energy use, accounting for 40–60% of typical electricity consumption. A heat pump (which provides both heating and cooling electrically) uses far more electricity than a gas furnace with central AC. The options in this calculator apply different kWh-per-square-foot multipliers based on each system type.

Add your electricity bill for better accuracy

When you enter your monthly bill and rate, the calculator blends the bill-based consumption estimate with the home-characteristics estimate. This hybrid approach improves accuracy because it accounts for your specific appliance load, occupancy patterns, and usage habits that square footage alone can't capture.

Set peak sun hours

Enter your peak sun hours for your location. Use our Peak Sun Hours Calculator for a precise value. The default 4.5 is the US average but varies significantly by region.

Review the cost estimate

The calculator provides a before- and after-ITC cost range using national average installation prices of $2.50–$3.50 per watt. These are rough estimates — actual quotes vary by region, installer, roof type, and current panel pricing. Always get at least 3 quotes from certified installers before deciding.

The Formula

The home-based consumption estimate uses area and HVAC type:

Estimated monthly kWh = (Home sq ft × HVAC factor) + (Bedrooms × 40 kWh) HVAC factors: No AC: 0.05, Window units: 0.07, Mini-split: 0.08 Central AC: 0.09, Heat pump: 0.14 If bill + rate entered: Bill-based kWh = Monthly bill ($) ÷ Rate ($/kWh) Final estimate = average of home estimate and bill estimate System kW = Annual kWh ÷ (365 × Peak sun hours × 0.86) Panel count = ceiling(System kW × 1000 ÷ Panel wattage)

The bedroom multiplier (40 kWh/month per bedroom) accounts for the plug loads, lighting, and device charging that scales with the number of occupants. A 3-bedroom home with 3 people consumes more electricity than the same floor plan occupied by one person, even with identical HVAC.

Example

The Williams family — Atlanta, GA

A 2,400 sq ft 4-bedroom home in Atlanta with central AC and a $200/month bill at $0.13/kWh. Atlanta gets 4.8 peak sun hours. Using 400W panels.

Home size2,400 sq ft

Bedrooms4

HVAC typeCentral AC

Monthly bill$200

Rate$0.13/kWh

Peak sun hours4.8 hrs/day

Result

Home-size estimate1,376 kWh/mo

Bill-based estimate1,538 kWh/mo

Blended monthly usage1,457 kWh/mo

Panels needed24 panels

System size9.6 kW

Cost after 30% ITC$16,800–$23,520

At Georgia Power's average rate of $0.13/kWh, a 9.6 kW system saves approximately $2,270/year. After the tax credit, the net cost of ~$20,000 implies a payback of roughly 8.8 years, with the system producing energy for 25+ years after that.

FAQ

How much solar do I need for a 1,500 sq ft home? ▼

A 1,500 sq ft home with central AC and 2 bedrooms typically uses 700–900 kWh/month. With 4.5 peak sun hours and 400W panels, you'd need 15–20 panels (6–8 kW system). With a heat pump instead of central AC, usage could be 1,100–1,300 kWh/month, pushing the system to 22–27 panels. Enter your specific details above for a precise estimate.

Does home size or electricity bill matter more for solar sizing? ▼

Your electricity consumption (kWh used) is what matters — not the dollar bill amount and not square footage. A 3,000 sq ft all-electric home might use 2,000+ kWh/month while a 3,000 sq ft home with gas heating and cooking might only use 800 kWh/month. That's why this calculator uses home characteristics to estimate kWh consumption, not just square footage. Always cross-reference with your actual utility bill when possible.

How does switching from gas to a heat pump affect my solar needs? ▼

Switching to a heat pump typically adds 3,000–8,000 kWh/year to your electricity consumption, depending on climate and home size. In a cold climate, it could add 10,000+ kWh/year. If you're planning electrification (heat pump, EV, induction cooking), size your solar system for your future all-electric load — not your current gas-heavy consumption. Change the AC type to "Heat pump" in this calculator to see the impact.

Is the cost estimate in this calculator accurate? ▼

The cost range ($2.50–$3.50/W) is based on national averages and should be used for ballpark planning only. Actual prices vary by: installer (up to 40% variation between quotes), state (Hawaii and Northeast run 20–30% higher), roof type (complex roofs cost more), panel brand, and current market pricing. Always get at least 3 quotes from NABCEP-certified installers. Use our Solar Cost Calculator for a more detailed breakdown.

Should I add a battery to my home solar system? ▼

A battery makes sense if: (1) your utility has time-of-use pricing where peak rates are 2–3× off-peak, (2) your utility has unfavorable net metering (paying you wholesale rates for excess), (3) you want backup power during outages, or (4) you have a critical load (medical equipment, home office). If your utility offers retail net metering, the battery payback is typically 12–18 years — the math doesn't support the cost unless backup is your goal. Use our Battery Calculator to model the addition.