How much can I save with solar panels?

Average US household saves $100-$200/month ($1,200-$2,400/year) on electricity with solar. Over 25 years (panel warranty life): $30,000-$60,000 in total savings. With net metering (selling excess power back to the grid), savings increase further. Savings depend on your electricity rate, system size, sun exposure, and utility policies. Higher rate areas (CA, HI, NE) see faster payback and higher total savings.

What is the payback period for solar panels?

Average payback: 6-10 years in most US locations. High-rate areas (California, Hawaii, Northeast): 4-7 years. Low-rate areas (Southeast, Midwest): 8-12 years. After payback, you get 15-20+ years of essentially free electricity. Factors: electricity rate, system cost, incentives, sun exposure. The 30% federal tax credit significantly shortens payback. Solar panels continue producing for 25-30+ years with only slight degradation.

How much electricity does a solar panel produce?

A standard 400W residential panel produces approximately 1.6-2.0 kWh per day depending on location (sun hours). Monthly: 48-60 kWh. Annual: 580-730 kWh. Production varies by season — summer produces 50-80% more than winter. Key factors: panel wattage, peak sun hours (4-6 hrs for most US locations), panel orientation (south-facing optimal), tilt angle, shading, and temperature (panels lose efficiency in extreme heat).

Solar Panel Calculator — Free System Size, Output & Savings Estimator for Any Roof 2026 | AllInOneTools

☀️ Electrical & Energy

Solar Panel Calculator

Calculate the number of solar panels, system size, daily/annual output, cost, savings, and payback period based on your electricity usage and location.

Your Electricity Usage

Monthly Electricity Bill

$/month

Electricity Rate

$/kWh

Your Location & Roof

Region (Peak Sun Hours)

Roof Direction

Panel Wattage

Cost per Watt (installed)

$/watt

📋

System Details

💰

Cost & Savings

📝 Step-by-Step Calculation

💡

Related Electrical & Energy Tools

Solar Panel Calculator: The Complete Guide to System Size, Cost, and Savings

Solar energy has never been more affordable or accessible. Panel costs have dropped over 70% since 2010, the 30% federal tax credit makes the investment even better, and most systems pay for themselves in 6–10 years — then generate free electricity for another 15–20 years. This calculator helps you estimate the right system size and see your potential savings.

The Solar Panel Formula

Monthly kWh = Monthly Bill ÷ Rate per kWh
Annual kWh = Monthly kWh × 12
System Size (kW) = Annual kWh ÷ (Sun Hours × 365 × 0.80)
Number of Panels = System kW × 1,000 ÷ Panel Watts
Annual Output = System kW × Sun Hours × 365 × 0.80
Cost = System kW × 1,000 × $/Watt
After Tax Credit = Cost × 0.70 (30% federal ITC)

Worked Example — Average US Home

Monthly bill: $150, Rate: $0.13/kWh
Monthly usage: $150 ÷ $0.13 = 1,154 kWh
Annual: 1,154 × 12 = 13,846 kWh
System size (5 sun hrs): 13,846 ÷ (5 × 365 × 0.80) = 9.48 kW
Panels (400W): 9,480 ÷ 400 = 24 panels
Cost: 9,480 × $3.00 = $28,440
After 30% tax credit: $19,908
Annual savings: ~$1,800 → Payback: ~11 years

Peak Sun Hours by Region

Region	Peak Sun Hrs	Example Cities
Desert Southwest	6.0-7.0	Phoenix, Las Vegas, Tucson
Southern California	5.5-6.5	LA, San Diego, Palm Springs
Texas / Southern Plains	5.0-6.0	Austin, Dallas, Houston
Southeast	4.5-5.5	Atlanta, Miami, Charlotte
Midwest	4.0-5.0	Chicago, Denver, Kansas City
Northeast	3.5-4.5	NYC, Boston, Philadelphia
Pacific Northwest	3.5-4.5	Seattle, Portland, Eugene

Pro Tip — The 30% Federal Tax Credit

The Inflation Reduction Act (IRA) extends the 30% Investment Tax Credit (ITC) for residential solar through 2032. This directly reduces your federal tax liability by 30% of the total installed cost. A $30,000 system gets a $9,000 tax credit. Many states offer additional incentives: state tax credits, rebates, SRECs (Solar Renewable Energy Certificates), and property tax exemptions. Check dsireusa.org for your state's specific incentives.

Important — Get Multiple Quotes

Solar installation prices vary 30-50% between companies for the same system. Always get 3-5 quotes. Compare not just price but: panel brand/warranty (25-year minimum), inverter type (micro vs string), monitoring system, workmanship warranty, and installer experience. Avoid companies that only offer leases or PPAs without explaining purchase options. Ownership (purchase or loan) provides the best long-term value and the tax credit benefit.

Frequently Asked Questions

How many solar panels do I need?▼

Divide annual kWh by annual production per panel. Average home (10,632 kWh) with 400W panels in 5 sun hours needs ~15 panels (6 kW). Larger homes or higher usage need proportionally more. Our calculator sizes the system based on your actual bill and location.

How much do solar panels cost?▼

Average: $2.50-$3.50/watt installed. 6 kW system: $15,000-$21,000 before incentives. After 30% federal tax credit: $10,500-$14,700. Prices have dropped 70% since 2010. Additional state incentives may further reduce cost.

How much can I save with solar?▼

Average: $100-$200/month ($1,200-$2,400/year). Over 25 years: $30,000-$60,000 total. Higher electricity rates = more savings. With net metering, excess production credits your bill. After payback (6-10 years), electricity is essentially free.

What is the payback period?▼

Average: 6-10 years. High-rate areas (CA, HI, NE): 4-7 years. Low-rate areas: 8-12 years. After payback, 15-20+ years of free electricity. The 30% federal tax credit shortens payback significantly. Panels produce for 25-30+ years.

How much electricity does a panel produce?▼

A 400W panel produces ~1.6-2.0 kWh/day (depending on location). Monthly: ~48-60 kWh. Annual: ~580-730 kWh. Summer produces 50-80% more than winter. South-facing, unshaded panels produce the most.

What is net metering?▼

Selling excess solar electricity back to the grid for bill credit. Your meter runs backward when producing more than you use. Available in 38+ US states. Credit rates vary: some offer full retail rate, others wholesale. Check your utility's net metering policy.

Do solar panels work on cloudy days?▼

Yes, at reduced output. Overcast: 10-25% of full capacity. Light clouds: 50-80%. Even Seattle and Portland are viable for solar — annual averages account for weather. Germany, with less sun than most US cities, is a top solar producer worldwide.