How to Pick the Correct Size for Your Portable Generator

Portable Generator Buying Guide

Power and electricity are essential in our current world–there’s no way around it. However, it seems that every time we turn around, something new is threatening our power supply, whether hurricanes, ice storms, tornadoes, terrorist attacks, civil unrest, or grid failures. Understandably, you want to be prepared to keep your family safe and in the best position to deal with these scenarios as possible.

Therefore, you may find yourself asking “How much power do I need?” and “What size generator is appropriate to keep my essentials running?”

While the answers to these questions can vary quite a bit, we will do our best to give you step-by-step requirements as well as an overview of the estimated wattage requirements of many common appliances.

First, you need to understand that there are two different wattage amounts for each generator. The ‘running wattage’ is simply the amount of watts the generator can handle as it runs. The ‘peak wattage’ or ‘starting watts’ is the additional wattage a generator can handle when a motor-driven appliance has a temporary surge upon startup. This wattage can spike above the running wattage, but only lasts for a short temporary period. Both of these wattage amounts will be listed for the different appliances below. 

Calculating the correct generator wattage requires three steps, and we will run through those first.

3 Steps to Finding the Right Generator Size:

Step 1: Make a list of the electrical appliances you would like to be able to power should you lose your source of electricity for a given amount of time. Write them down or track them in a spreadsheet. These appliances can range from large items (e.g., your AC, heater, oven, TV, stove) to smaller items (e.g., laptops, cell phones, Xbox).

Step 2: Track the wattage required for the various appliances you would like to be able to power. Track both the running watts as well as the peak watts because both are required in determining the size and type of generator that best fits your situation. 

Step 3: Add together the running watts of all the different appliances that you would like to power at the same time. After you find your total running wattage, find the appliance with the largest peak wattage and add that together with your running watts total. This simple addition will give you both the needed running wattage and peak wattage of your generator. 

Example #1

For simplicity, let’s review a quick example: Below are the running watts and peak watts for John’s refrigerator, sump pump, television, and washing machine. He wants to be able to power all of them should he lose power. John was thinking of getting a 4000 watt generator (4000 peak, 3500 running). Would it be large enough? Let’s take a look…

ANSWER: The total running watts are only 2685, so he would be good with the running wattage limit of 3500. However, because the peak watt limit (total running watts + largest peak watt amount) was 4935, John would have to find a different generator with a higher peak wattage.

Wattage Requirements of Common Appliances

Now that we’ve broken down the basics, let's look at some potential appliances you may be interested in powering. Check them out below.

*The wattage amounts provided in the charts above are simply estimates and should not be assumed to fit every different situation. We recommend you check your specific appliances before ordering a portable generator.