P3 International Kill A Watt


Pros: Easy, informative

Cons: Might have more features than most people want

When you get your power bill at the end of the month, it probably tells you how much you used in gas vs. electricity, but that's about it. Some months the bill goes up, some months it goes down. But do you really understand why? This product can help.

A friend loaned me one of these for a few months and it really helped me understand power usage around the house. It's pretty simple. You plug it into the wall, and then plug your electrical appliance into it. The digital readout tells you how many watts the appliance is using. It's that easy. It has a few options, too, that can provide more information.

For example, you can leave it on all night and it will tell you how much cumulative power the appliance used overnight. This is helpful for things like refrigerators, where the power usage goes up and down as the internal mechanisms switch on and off again. It helps to learn a couple of basic concepts like what a kilowatt-hour is, and amps versus watts. But even if you don't understand all that stuff, you can start comparing different appliances around your house to each other, and find the big power suckers.

For example, we had this great hot-water-kettle we loved to use. Basically, it's a sealed thermos with a pump spout. You plug it in, and then just leave it on. It keeps water piping hot all the time. You never have to wait for the kettle to boil, just go up and get hot water when you want it. It made morning coffee much faster! HOWEVER, using the Kill A Watt, we learned that this thing eats up 80 watts of power continuously to keep the water warm.

Would you leave an 80-watt lightbulb on 24/7 just so you could make coffee 5 minutes faster? We unplugged the thing. Other interesting things we learned were how much power appliances use when turned off. It turns out our TV uses almost 5 watts just sitting there, listening for the remote control to turn it back on. Many other electronics devices around the house do the same thing, and we've started unplugging the ones we don't use often, sometimes re-routing the cords to make this easy to do.

We also learned that our electrical radiators use an absolutely astounding 1500 watts when they're turned up to high. We thought we were smart for not running the central heating, but it turns out that our central heating might be more efficient than two of those space heaters.

And we invested in a 4 watt electric heating pad for our cat to sleep on so we wouldn't have to run a 1500 watt space heater in her room overnight. Once you have the numbers, a lot of these decisions become obvious. Kill A Watt gives you those numbers. 

I definitely recommend this for anyone who cares about saving money and energy. Learn the basic functions and start testing around the house!


Pros: Helps me plan power saving strategies and determine vampire power.

Cons: ...non yet.

I have used this device for a couple years now - helps me determine what actual power usage is from various devices and appliances around my home.  I mainly use the "watts" and "Kilowat Hours/Clock" features.  Easy to use.  Small to store.  It allows for quick tests for vampire and other loads, or you can leave it plugged in - to a refrigerator, for example - for a week or month.


I tested my fridges for a full month to get the various usage and power cycle loads captured over time - was very VERY handy for that. 


Love it!!!


Pros: Inexpensive

Cons: Could be more accurate

This is a very useful product, which can help reduce your power consumption by determining how much power each electrical device/appliance you have uses.


The two primary modes of operation are: 1) Watts, where you can measure instantaneous power consumption, and: 2) Kilowatt-hours, where you can determine average power consumption over extended time periods.  The first mode is more effective for devices that use the same amount of power all the time (like a light bulb), the second mode is more effective for devices that vary their power consumption over time (like a refrigerator).


My one complaint would be that it seems to read low by one watt (approximately).


Pros: You won't believe what your appliances use!

Cons: I need a 220 volt version with higher amperage capability.

I was amazed at the differences in my 2 full size refrigerators. The one I thought was newer and more efficient used 67 KW per month. The one I WAS going to replace uses 42 KW per month. Money well spent!


Pros: small, inexpensive, accurate,

Cons: no backlighting

The main reason that Prius drivers get such good mileage is arguably not because they are such efficient cars, but that the real-time feedback of mileage makes drivers radically change their behavior.  Enter the Kill-A-Watt.  I bought one for my residential energy audit company last year and use it every time I go on site.  I basically plug an appliance into the device, get a readout, and take a picture.  This seals the number and appliance's energy usage into the customer's brain.  From then on out they know exactly how much power it uses.  It can really change the way people act in a very concrete way.  Buy it for your own home for a similar revelation.


Pros: kill those Watts!

I love my Kill-A-Watt.  I use it mostly to monitor how much energy it takes to recharge my EVD electric moped.  It's also useful for figuring out how much energy various appliances are using, and whether you've got any problems with vampire power.


Very simple to use - just plug your appliance into the Kill-A-Watt, which gets plugged into the power outlet.  Then the various buttons tell you how many watts/amps/vots the appliance is drawing.  The pink button keeps a running tab of how much energy (in kilowatt-hours) your appliance has sucked up.


It's a really useful tool to have around the house!

P3 International Kill A Watt

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. Large LCD display will count consumption by the Killowatt-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. Large LCD display Cumulative Killowatt-Hour Monitor Forecast Your Costs Also display Volts, Amps, Watts, Hz, VA 0.2% Accuracy

Additional Features
TypeEnergy monitor or meter
Release Date
Model Name/TypeMPNEAN/UPC

P4400 Kill A Watt TM Operation Manual

Congratulations on your purchase of the Kill A Watt™ Power Meter. Cared for properly, this unit will provide you
with years of service.

  1. The LCD shows all meter readings: Volts, Current, Watts, Frequency, Power Factor, and VA. The unit will start to accumulate KWH and powered duration time (hour) after power is applied.
  2. Press Volt Key for true RMS Voltage (Volts) display.
  3. Press Amp Key for true RMS output current (Amps) display.
  4. The Watt/VA Key is a toggle function key. Press the Watt/VA key once to display Watt meter, then press key to display VA meter. The LCD will display Watts as the active power, where VA is the apparent Power. (VA=Vrms Arms)
  5. The HZ/PF is a toggle function key. Press the HZ/PF key once to display the frequency (Hertz), then press key to display the Power Factor. HZ is the Frequency of output Voltage, where PF is the Power Factor (PF=W/Vrms Arms).
  6. The KWH/Hour is a toggle function key. Press the KWH/Hour key once to show the cumulative energy consumption since power was applied to the unit. Then press key to display the cumulative time since power was applied to the unit.
  7. Consumption will be displayed in Kilowatt-Hours (from 0.01 KWH to 9999 KWH). Time will initially be displayed as Hours:Minutes (from 00:00) and switch to Hours (to 9999). Counters will recyle to zero when they reach their maximum. To reset, remove power from unit momentarily.


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Kill A Watt Meter Alt-E Video Tip



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