Portable Generator Wattage Calculator

Calculate the perfect portable generator size for your needs

Select an option below

Do you intend to use your generator at high altitudes?

⚠️ Generator power decreases by approximately 3% per 1,000 feet above sea level. Learn more>

Add Custom Appliance

⚠️Caution: Our Generator Size Calculator is advanced. but no matter what their accuracy Wattage claim. Never use generator calculator alone to make decisions, always verify your results with a professional before making decisions that could affect your system or safety.

Generator Wattage Calculator Tool

This tool is for estimate your wattage needs. It assumes that not all appliances will be used at the same time. Transfer switches should be sized for your specific situation. We recommend having a licensed electrician check your electrical needs before you buy anything. A certified electrician should do all installations to follow local codes and keep your warranty valid.

If you don’t know how to calculate the wattage needed for a generator, it is important to select the right one for your home, RV, or worksite load. This guide explains how to use a generator sizing tool, add custom devices, and includes easy-to-understand pictures to help you calculate wattage on your own.

Why Use Generator Fixer Wattage Calculator Tool? 

Whether you’re a house owner or a professional, sizing calculator unique features help you find the desired wattage shine.

The Generator Fixer wattage calculator tool allows a simple process of calculate your power needs. It provides perfect estimates to help you choose the right generator size without guesswork. Whether you are planning for whole-house backup or worksite use, this tool ensures you’ll make an informed decision.

Why Know Your Wattage is Important

What size generator is needed to run your house, wattage helps you choose a generator that meets your needs without overloading or underutilizing. It also ensures safety and proper appliance function.

How To Use Generator Size Calculator

First, identify your devices and list the electrical appliances or tools you plan to power with the generator.

Find the power rating (in watts) for each appliance. Note down running Watts and starting watts. Include refrigerators, lights, heaters, microwaves, tools, etc.

Generator Wattage Calculator 1

This information is usually found on the appliance’s label or manual or our wattage chart. If you’re unable to find the wattage for a specific appliance, you can estimate typical wattages using the U.S. Department of Energy’s Home Appliance Energy Calculator tool.

categories

Step 1: Select a Category Opt

The available calculator has three categories

Home

Household & kitchen devices

Recreational

Camping, RV & outdoor activitie

Professional

Tools & heavy equipments


Select a Category Opt
Browse or Search Appliances
Use Filter

Step 2: Browse or Search Appliances

Browse or Search Appliances
  • You can scroll through the list to find the appliances you want to use. You can also search for specific appliances using the “Search appliances” bar.


as Need

Step 3: Select Appliances With Count

Each appliance shows two types of wattage. Running and starting watts. Select devices and count 1 or 2 etc.

Running Watts: The power required to keep the appliance running
Starting Watts: The extra power needed when the appliance starts

Select Appliances With Count
Adjust for High Altitude Use
Keep in Mind

Step 4: Adjust for High Altitude Use

Adjust for High Altitude Use
  • If you plan to use your generator at high altitudes, select “Yes” for this option. Generators may lose efficiency at higher altitudes.


Optional

Step 5: Add Custom Appliances

f your appliance is not listed, you can sample add it manually.

  • Enter the name of the appliance
  • Enter its running watts
  • Enter its starting watts (if applicable)

Hit the button “Add Custom Appliances”.


Add Custom Appliances
Calculate Total Wattage
Keep in Mind

Step 6: Calculate Total Wattage

  • Click the “Calculate Generator Size” button and wait for the result to view your desired estimated generator size.


Reviewing Your Results

The results will show the total wattage you need. Use this information to choose the right generator.

Contact Us for Assistance

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