How to Calculate Your Solar Cost

Good news – I’ve combined the solar cost calculator with the solar sizing calculator. Now you can estimate both in one easy-to-use calculator.

Head on over to the article Calculate Solar Array Size and Cost.

If you have any questions – feel free to shoot me a message on my contact page.

For history’s sake, here is the old article.

Step 1:

Calculate your solar array size.

Step 2:

Estimate your cost per Watt installed.

Hint: If solar is popular in your state (CA, CO, NJ) and you have asphalt or composite shingles, then use $4-$6/W. If solar is less popular in your state (VA, TX, MI) and you have a tile roof, then use $6-$8/W. If you’re unsure, $5.5/W is about the National average.


This calculator assumes no State or Utility rebate. Go to to see if your area offers solar incentives. If it does, subtract it first from the Estimated System Cost. This is your total cost of installation.

Then calculate the Fed Tax credit by multiplying the result by 30% (0.3). Lastly subtract the Tax credit from the cost of installation to get your Total Cost after all incentives!