Watt Calculator: How to Calculate Watts

Get amped up with our watt calculator

Photo: MoMo Productions / DigitalVision / Getty Images
Photo: MoMo Productions / DigitalVision / Getty Images
Highlights
  • Watts measure the amount of electrical power being used at a particular moment.

  • Learn how to calculate watts to get a better handle on your home’s electricity use.

  • To find the wattage of an appliance or device, multiply the amps by the voltage used.

  • The higher the wattage, the more power is consumed.

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Trying to cut back on your energy costs? Understanding how much electricity your appliances use is a good starting point. To do that, you’ll need to learn how to calculate watts—or the amount of power consumed by an electrical product. 

How Many Watts Your Appliances Use

At any given moment, the average house uses 1,083 to 1,375 watts of electricity. However, your home’s watt usage could be lower or higher, depending on your energy consumption habits. 

Here’s an overview of some common household appliances and their watt usage:

ApplianceAverage Watts Used
Light bulb7–100
TV50–200
Refrigerator400–1,300
Coffee maker500–1,500
Hair dryer750–1,900
Microwave800–1,000
Dishwasher1,200–2,400
Central air conditioner3,000–3,500

How to Calculate Watts for Your Home Appliances 

Looking for the wattage of an appliance? You’ll often see it on the product label, packaging, or metal nameplate. If you can’t find it, you can use the following formula to determine the wattage of an appliance: 

Watts = Amps x Volts

How to Find Amps and Volts to Calculate Watts

Electrical terms compared to water in a hose, with amps equaling the water volume or how wide the spigot is open

Before you can calculate the wattage of an appliance, you’ll first need to determine its amperage and voltage. For reference, amps (or amperes) measure the volume of electrical current, while volts describe electrical potential (or the “pressure” that pushes electrons along).

Like wattage, the easiest way to find amperage or voltage is by looking at the product label or user manual, both of which should list the product’s electrical requirements. If that’s not an option, you can check the manufacturer’s website or call a local electrician.

Who to Hire for Electrical Work

Electrician fixing an electrical outlet
Photo: andresr / Adobe Stock

It’s safest to hire a licensed electrician for any type of electrical work in your home. It may even be required by law, depending on the nature of the project and where you live.

Whether you’re adding new power outlets, installing lighting, or rewiring your house, here are some questions to ask electricians during the interview phase: 

  • Are you licensed, insured, and bonded?

  • Are you experienced with this type of project?

  • Will you bring in any subcontractors? If so, how many and are they covered under your insurance?

  • Can you share references?

Frequently Asked Questions

An air conditioner’s watt usage depends on multiple factors, including the type of AC unit, its size, and how often you use it. With that said, most central air conditioners consume between 3,000 and 3,500 watts. Meanwhile, window AC units use 900 to 1,400 watts, and portable air conditioners consume 2,900 to 4,100 watts.

In many cases, yes, upgrading your electrical panel can lower your electric bill. Upgrading an outdated electrical panel can make your home more energy-efficient, so you consume less electricity and spend less on utility bills. However, to see these savings, you’ll need to invest quite a bit. On average, installing a new electrical panel costs $1,200 to $2,000, with most people paying around $1,600.

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