Free Solar Calculator: Estimate Savings, Costs & Payback Period (2026)

How Our Solar Calculator Works

Our free solar calculator uses industry-standard formulas to estimate your solar potential. Here's what we calculate and how:

Inputs We Use

• Zip Code: Determines your location for sunlight hours and state electricity rates
• Monthly Electricity Bill: Helps estimate your annual energy consumption
• Electricity Rate: Used to calculate your current energy costs
• Panel Wattage: Determines how many panels you'll need for your system

Key Calculations

1. Annual Energy Usage: Monthly Bill × 12 / Electricity Rate = Annual kWh Usage
2. Required System Size: Annual kWh / (Sunlight Hours × 365) / 0.80 (system efficiency)
3. System Cost: System Size × $2.75/Watt × (1 - 0.30 tax credit)
4. Annual Savings: Annual Bill × 0.95 (accounting for efficiency losses)
5. Payback Period: System Cost / Annual Savings

Assumptions We Make

• Average system efficiency of 80% (accounts for inverter losses, shading, etc.)
• Current federal solar tax credit of 30%
• Average installation cost of $2.75 per watt
• Standard panel size of 17.5 sq ft per panel
• 95% of your electricity bill can be offset by solar

Why Go Solar?

Solar energy offers numerous benefits including:

• Reduced electricity bills by up to 95%
• Lower carbon footprint and environmental impact
• Increased home value and property appeal
• Protection against rising energy costs
• Federal and state tax incentives

Factors That Affect Your Solar Savings

Several factors influence your solar savings:

• Your location and average sunlight hours per day
• Local electricity rates and net metering policies
• Solar panel efficiency and quality
• System size, orientation, and roof angle
• Available federal, state, and local incentives
• Your current and future energy consumption patterns