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P3 International

Kill A Watt®
Realtime power monitoring device

Empowers you to save $100's on electric bills!
Electricity bill are rising. Now you can cut down on costs and find out what appliances are actually worth keeping plugged in. Simply connect these appliances to the Kill A Watt®, and it will assess how efficient they really are.

The large LCD display will count consumption by the Kilowatt-hour, same as your local utility. You can calculate your electrical expenses by the day, week, month, even an entire year. Also check the quality of your power by monitoring Voltage, Line Frequency, and Power Factor.

Now you'll know if it is time for a new refrigerator or if that old air conditioner is still saving you money. With the amazing Kill A Watt you'll know "Watts" killing you.
  • LCD Display
  • Cumulative Kilowatt-Hour Monitor
  • Forecast Your Costs
  • Also displays Volts, Amps, Watts, Hz, VA
  • 0.2% Accuracy

Product Specifications:

P3 International Part Number

  • P4400

Operating Voltage

  • 115 VAC

Max Voltage

  • 125 VAC

Max Current

  • 15 Amp

Max Power

  • 1875 VA


  • 5.1" x 1.1" x 2.4" (20.9 x 2.8 x 6.1 cm)


  • 5 oz. (142 g)


Manufacturer provided specifications for P3 International p/n P4400 UPC#: 751549044009


Customer Ratings

Write a Review 4.5 / 5 4 out of 4 (100%) reviewers would recommend this product
Reviewer: Xercos Location: Spanish Fork, UT Age: 55-65 Experience Level: IT Professional Owned Product: over 6 months
Rating: 5/5 Worth its weight in gold! July 14, 2017 Well, it isn't too heavy. But I love this thing!

I have had one of these for years, and it has been an eye-opener! How much does it cost to run my servers for a year? Now I know. I measured a day's worth of juice and now can give the IRS a fact-based value. Is it worth having a soda vending machine in the break room? Only uses 60¢ of electricity a day, so, yes! What size UPS do I need? Can I watch the heat turn on and off on the griddle? Why does that breaker keep tripping? Does this outlet work?

I've lent it to several friends for their own electro-financial research. Very, very useful!

I would recommend this item to a friend!

Reviewer: Anonymous Location: Huntsville, AL Age: Over 65 Experience Level: Power User Owned Product: over 6 months
Rating: 4/5 Excellent, but minor limitations January 13, 2016 I have owned a Kill-a-Watt P4400 for a long time. Overall, it's quite good at what it does. It's a proven product, but has some physical design limitations. 1. The display is not illuminated, so it's hard to read in a dark room or in a low power outlet. 2. The body of the Kill-a-Watt blocks adjacent outlets if you plug it into a standard wall socket, or into a power strip with closely spaced outlets. Look at OWC's Image #3. If you need access to the other wall outlet, the work-around is simple: use a 3-wire extension cord between the socket and the Kill-a-Watt. That trick can also put the Kill-a-Watt in a more-convenient location for you to view the display, like on top of the fridge instead of behind it. 3. It has only one outlet itself. Not perfect, but it will definitely help you identify and mitigate household power-suckers. Mine was made in China, and it's still working well after many years. Great to see OWC now selling this product.

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: Brazil Age: 55-65 Experience Level: Power User Owned Product: over 6 months
Rating: 4/5 Efficient! March 26, 2013 Sorry my grammar. ;) I have two units and works as advised.

I would recommend this item to a friend!

Reviewer: dana Location: Connecticut Age: 55-65 Experience Level: Home User Owned Product: over 6 months
Rating: 5/5 Can pay for itself many times over November 24, 2012 I have had one of these for several years, and it has more than paid for itself by identifying devices and appliances that use more than their share of electricity.

For example, most electronic devices draw some power while turned off. Usually this is a watt or less, but I have found some older devices such as a VCR which drew about 10 watts. That's about 90 kilowatt hours per year, which was costing me about $0.15 per kilowatt hour, or about $13 per year. Unplugging that plus a few other inefficient transformer-operated devices paid for the meter within a year. To identify these, I only had to plug them into the Kill A Watt and note the wattage. Since there are 8,760 hours (8.76 kilo hours) in a year, the cost of running a device for one year is:

watts * 8.76 * electric rate

For devices like air conditioners or refrigerators, it's necessary to run them on the meter for at least a day, then determine the average wattage. From that you can estimate the yearly cost. For example, I found out that an old upright freezer in the basement used 3.54 kilowatt hours over a period of 26 hours and 29 minutes. That works out to nearly 1200 kilowatt hours (1.2 megawatt hours!) per year, so it was costing me about $180 per year. It turned out we could unplug the freezer and consolidate our frozen food into the refrigerator.

I would recommend this item to a friend!

P3 International Kill A Watt Realtime power monitoring device Mfr P/N: P4400 OWC SKU: P3IP4400 See exactly how much your devices cost to run. Connect your appliances into the Kill A Watt, and assess how efficient they are. P3 International 6 Month Warranty
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