Residential Air-Cooled Generator Sizing Calculator

We have designed this sizing calculator to help you streamline the process of determining the right size equipment your customers' backup generator needs. Used properly, this will become a valuable tool in your arsenal, and can help you bid jobs faster, and with better accuracy. 

Click here to download the Generator Sizing Calculator Template


You must have Microsoft Excel 2007 or later to open this file. If you use Google Sheets or any other spreadsheet application, you may need to adjust some of the formatting and print settings to get it to work properly. 

Be sure to replace the Better Power logo with your own before printing.

 Click this image to download the template. 

Click this image to download the template. 

The calculator has been pre-filled with sample values. Replace the sample numbers (in blue) with your own real values to get an accurate calculation. 

Helpful NEC code information is located along the right. This is for your reference and will not appear on the final print-out.

When you're finished, you can print this document for your own records or to share it with your customer as part of a price quote.

This calculator is intended for whole-house residential applications. We also have selected circuit, and commercial generator sizing calculators available upon request. 

Please call or write if you need help using this template, or if you would like access to one of our other sizing calculators or guide books. We're here to help!

1-800-475-1321 | Gary@BetterPowerOnline.com