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P3 P4400 Kill A Watt Electricity Usage Monitor

(10 customer reviews)

Price: $39.95
Sale Price: $33.45

You Save: $6.50

Choose from the Kill-a-Watt’s four settings to monitor your electrical usage
Monitor your electrical usage by day, week, month, or year
Features easy-to-read screen
Electricity usage monitor connects to appliances and assesses efficiency
Large LCD display counts consumption by the kilowatt-hour
Calculates electricity expenses by the day, week, month, or year
Displays volts, amps, and wattage within 0.2 – 2.0percent accuracy
Compatible with inverters; designed for use with AC 115-volt appliances

Brand P3



P3 P4400 Kill A Watt Electricity Usage Monitor

Empowers You to Save Hundreds on Electric Bills

Electricity bills 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 counts consumption by the kilowatt-hour, the 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 will know if it is time for a new refrigerator or if that old air conditioner is still saving you money. Kill A Watt can help you reduce your power bill and will help find power-wasting appliances so you are able to decide whether it is worth keeping them plugged in. For standard 115 VAC appliances only, 15 amps maximum, 125 VAC maximum.

Find Out How Much Electricity You’re Using

The U.S Department of Energy reports that 20% of our electric bills come from items that are left plugged in when they are not in use, or items that are in standby mode. With the Kill A Watt P4400 we can monitor the energy eaters in our homes and cut down our electric bills at the same time. Plug whatever item you want into the device and it will tell you the efficiency of that item by displaying the kilowatt per hour. This device will help you determine which items are costing you the most to run. The Kill A Watt also calculates voltage, line frequency, current, and power factor. You can calculate your electric bill before you even receive it from the electric company.

Test The Quality of Your Home’s Power

But measuring appliance consumption is just the tip of the iceberg. Because it can monitor voltage (Volt) and line frequency it can also test if an outlet is working, or evaluate the quality of the electrical power provided by your utility company. It can detect voltage drops around the house, help to predict brownout conditions or to make sure a new home’s outlets are in working condition before escrow closes.

About P3 International

Founded in 1987, P3 International is a privately owned manufacturer of solution oriented consumer products. For the last twenty years they have strived to develop products that are easy to use and ahead of their time. Thanks to their customer-centric attitude and support from their clients, they have experienced steady growth over the past decade.

They are committed to manufacturing high quality products that appeal to a variety of different people, from the environmentally conscious to the more technologically-minded consumer. With this philosophy driving them they are always looking for innovative new products which they can offer their customers.

Their unique products have garnered much attention, in particular the Kill A Watt. Reviews of P3 products have been featured in newspapers such as The New York Times and The Wall Street Journal.

Technical Specifications

  • Accuracy: +/- 0.2%
  • Input Power: 115 volts AC, 60 Hz
  • Max Current: 15 amps
  • Max Voltage: 125 volts
  • Max Power: 1875 VA
  • Dimensions: 5.1 inches long x 1.6 inches thick x 2.4 inches wide
  • Approvals: ETL (c), ETL (us)
  • Origin: China
  • Manufacturer Warranty: 6 months

Additional information


2 Pack, 3 Pack, 4 Pack, 5 Pack, Original version



10 reviews for P3 P4400 Kill A Watt Electricity Usage Monitor

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    This meter does exactly what I wanted it for: to double-check my multi-meter readings and do quick readings to avoid having to get the meter out at all — and the math. I do not leave it connected all the time, I take a reading and react accordingly.Watt readings using a meter, for instance, requires finding two Ohm’s Law variables –usually requiring a dummy load setting if done real-time with a multi-meter — a setting derived while not actually doing work, which can change the load characteristics. So this meter takes those real-time readings more quickly and efficiently. Another example: Checking current requires metering in-line or splitting a cable to isolate a wire for clamping; sometime this is inconvenient and requires remembering to use the meters fused lead. It just does things quickly, less pain.For those who are not into electronics, it’s a quick way to check specs from overseas companies whose stats can be a bit hyperbolic.

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    Okay. I’m a Believer. This kilowatt is amazing. I couldn’t stop using it as soon as I opened the Box.I even take this thing with me to visit friends and families for Thanksgiving to Sheldon how much energy usage they’re using even when they think they’re Appliance are off. It’s amazing to see which items are your energy vampires. I never even realize that the cable box was using so much energy. I unplugged it at night when I went to sleep. And plugged it back in in the morning on a outlet bar. And I saw the Amazing Savings on my next electricity bill. You will be amazed. If you don’t believe it, just buy one. You’ll want to buy more.I can’t stop caring mine. I want to knock on my neighbor’s door and try other devices on it.😉😊

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    I have had one of these Kil-A-Watt devices for years. With this product, I figured out what lighting options were the cheapest to use. Example: an LED bulb I purchased had been advertised as 32-watts. Using the Kil-A-Watt device, I found that was a falsehood, the bulb in question was only using 8w…Not the advertised wattage of 32w (A 5-watt savings over the CF bulbs that I was replacing with a brighter, lower wattage LED). Over time, I have cut my electric bill just over 70 dollars going from regular incandescent bulbs to (CF) Compact Fluorescent and then to LED bulbs.I also figured out what power supplies were the most efficient through the PF Setting (PF = Power Factor. PF is a measurement that informs you about a transformer’s efficiency) A perfect PF reading is 100, which cannot happen because transformers are not perfect. The little 8 dollar China made 12volt – 6amp transformer to power LED strip lighting usually have a PF of 67, meaning that they are 67% efficient at converting 120 volts to 12 volts. NOTE: A computer power supply is normally between 85 – 93%. The higher PF factor cuts cost over the long run, is more efficient, and creates less heat during the conversion of 120v AC to 12v DC. The lower the heat output, the longer the transformer will last.

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    Quite interesting to use. 1800w max rating, and the highest watts I’ve measured was from a 1980’s microwave pulling 1450ish watts. It’s just very fun to guess and then check the watts that appliances use. There’s more than wattage, of course, as you can see amps, volts, and even measure kilowatt hours… which if you’re serious about monitoring your electricity usage, that setting will probably come in the most handy.

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    remote camper

    UPDATES at end of the review.Several reviews show the receptacle melted after using them with appliances that draw a fair amount of current. This should not be happening because these units are fused with a SEFUSE Thermal cutoff (at least mine is). I found out by using the device in a manner I knew was a little risky. Temp environment was over 106*F ambient and knew I was using it potentially at its upper limit. Well, it did fail and instead of throwing it away, took it apart to see if it was beyond repair.My rating is based on my experience with it over the last 3 years or so and the great service it has given me. I should probably add that the fact it failed under extreme use without melting the receptacle is also testament to its safety design and warrants some credit.The SEFUSE has a TEMPERATURE rating in addition to in this case, a 15 AMP current rating. For replacement parts, I have seen these rated between 128*C to 240* C. I guess the theory is that it can be used up to it max rating as long as the temperature rating of the installed SEFUSE is not exceeded. If this thing starts to go above the SEFUSE rating, the SEFUSE should fail well before the monitor’s receptacle starts melting! I would guess that the Kil-A-Watt folks *might* have used a SEFUSE with a higher temp rating in some production runs than the original design called for. It might also be possible that the SEFUSES received by the mfr were faulty or mislabled. There might be some warranty wiggle room here for those where the monitor started melting. It was designed not to do that!My SEFUSE is *open* indicating that it did its job to prevent overheating the plug/unit. I have to look closer at it to see if I can determine the rating, otherwise I will have to take the new 4440 I just ordered apart and look at that one. There are ways to test to see if replacing the SEFUSE is the problem, but won’t go into it here for liability reasons. SEFUSES are available on Amazon at a pack of 5 for under $10. Looks like a stout soldering iron will be needed to effect the repair if you want to pull the old leads from the board. I have done similar repairs by cutting the leads of the failed component and installing the replacement matching its lead length to the original installation. A much lesser wattage soldering iron will do the trick.I like mine and needed a second one anyway. I am fairly certain replacing the SEFUSE in mine with one of the correct rating will restore original safety design and operation. I do not encourage user replacement of any components in this monitor. This review serves only to explain my experience and what I plan to do to try to correct it.UPDATED 9/19/2019The SEFUSE was in fact the issue. If one does a search on Disassembly and Repair of the Kil-A-Watt meter, a video will likely be available on the topic. The SEFUSE in this instance was rated at 99C (210F) in addition to its current rating. A word of caution here. I have seen this component with temp ratings spanning 77C to 240C at 15 amps. It is available with the same rating at 10 amps. The closest one I can find on Amazon is 94C (201F) at 15 amps. If you decide to take this on, be SURE you do not exceed 99C for the replacement component. Since it is available in such a broad range, it reinforces my theory somewhat that some production runs were using the wrong value on the low end (causing early failure) as well as perhaps on the high end (causing the case to melt). This doesn’t excuse the failures, but offers some explanation as to what might be occurring. As long as the case is not damaged, this is likely an easy repair for someone with this type of skill. The 94C component is close enough for me.UPDATE 9/23/2019New meter arrived and the SEFUSE checks out at 15A/99C. Back of meter rated @1800W. MAX Power on packaging states 1875W. Would use the meter only for a quick measurement and NOT for sustained use much above 50% of its rating. Will just order the 94C SEFUSE from AMZ. to repair the old one.

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    Stephen Throop

    I bought a P4400 in 2011. It showed which household items were power vampires, some using as much power off as on. I could switch them off with power strips or unplug them when not needed.By measuring the power consumption of internet-related equipment, I could estimate how much time a given UPS could give me in the event of a power failure.I kept a spreadsheet of wattage of various items under different conditions, to help future troubleshooting. When my internet speeds slowed down, the P4400 showed me the culprit. The power consumption of the $4 power supply of my VOIP telephone adapter was abnormally high.For the refrigerator, I measured KWH per day for a summer kitchen temperature and for a winter kitchen temperature. After that, the P4400 could show me if the refrigerator was still operating as efficiently, or maybe I needed to check for dust or ice.If a refrigerator wasn’t cooling, the P4400 was a quick way to see if the compressor was drawing current.Last year, I bought a smart charger for car batteries. It had no ammeter. Clipping in a multimeter would have risked a short, a disconnection, or damage to the meter. I plugged the charger into my P4400, and with the multimeter, I determined how many watts the charger needed for each amp out. Then I didn’t need the multimeter. By showing me input wattage, KWH, and time, the P4400 let me know output amps, amp hours, and charging time.The other day, my P4400 was in the engine compartment of a truck as I charged the battery. In case of an unexpected shower, the hood was up only three inches. In a sudden, heavy shower, enough drops blew through the crack to wet the P4400. It still gave credible wattage readings, but not KWH or amps.I bought another one immediately. The P4400 has proved its value.Update: Last year I bought an electric chainsaw. I finally got around to using the P4400 to see if the manufacturer’s horsepower claims are true. Apparently so. It also showed me how much voltage I was losing by using 150 feet of extension cords. The flashing display of the P4400 warned me that the current could damage it if I ran the saw more than a few seconds.The manufacture recommends 14 gauge cord or larger. My cords aren’t marked. To test, I used an electric skillet. Unlike the saw, it’s a resistive load, and it doesn’t draw enough current to endanger the meter. First I plugged the P4400 into an outlet and plugged the skillet into the P4400. I noted the voltage drop when I turned it on. Then I plugged an extension cord into the outlet and plugged the P4400 and skillet into the cord. I noted the voltage drop and the amps.I subtracted the voltage drop at the outlet from the voltage drop at the end of the cord to determine how many volts I was losing in the cord. Dividing that by the amps gave me ohms. In the cord, current runs through the hot and the neutral in series, so the path is twice the length of the cord. To get ohms per foot, I divided the ohms by twice the cord length.Knowing ohms per foot, I could look up the gauge online. My cords are 16 gauge. I can probably get 2.5 horsepower with them. I might get 2.75 horsepower if I upgraded to 14 gauge cords. I’m satisfied with 16 gauge.

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    Ed Kashin

    I have known about the Kill A Watt for quite some time. After taking a class in ways to make your home more energy efficient, I decided to get one and find out exactly how much electricity those little gizmos that sit and do nothing much of the time actually waste. No real surprises, though, as I know these things (anything with a light on when not in use) use power when idle. Simply unplugging them saves a bit. The one big surprise did come when I measured the “idle” usage of my home theater gear (TV, Amp and BR player). It was well over 50 watts! Enough to light the room 24 hours a day. A simple power strip with surge suppressor that can be shut off solved the problem. Everything comes on just fine after powering up the strip. Though I haven’t figured out how many dollars I have saved since figuring this out, I’m positive the cost of the Kill A Watt has been recouped (at least) and I am saving quite a bit of power I didn’t need to be using. I highly recommend this unit as a simple way to take stock of anyone’s home electric usage.

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    This did exactly what I needed it to do. I have a lot of computers, monitors and other electronic devices in my home office. I recently became aware of some other devices (like space heaters) that can cause house fires due to over-taxing the 15amp circuit. This caused me to wonder about what my entire collection of office devices are doing to that circuit, so I now have all devices plugged into surge protectors, which are plugged into one UPS, which is plugged into this P4400, which is plugged into the wall outlet. With everything powered up and online, the reading on the P4400 doesn’t go much over 5.1 amps. That’s great news! So, again, this device allows me to monitor my amp usage for my whole office. Works great!

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    works. mine is showing real usage but for some reason the counter showing time resets on mine every 24 hours. it will keep the kilowatt used without resetting that part, but no matter what i do with mine the clock rolls back to zero at 24 hours. (it should not do this, it should keep a time log for the whole time its plugged in up to 999 hours)does NOT remember anything after its been unplugged. some people seem to think this will keep a history of what its logged BUT if you unplug it from power it loses everything in its memory.PRO’s1…does what it says it will do2…can give you a great way to find out how much juice something is using3…has a nice sized read out bigger then a lot of hand held meters4…let me find out that my cable box’S are drawing 550 watts PER-BOX constant draw even when “powered off”!!!!5…showed me my freezer in a open air garage in Florida is more energy friendly then my fridge in the houseCON’s1…will cover 1 of the 2 outlets in a double socket outlet, the unit is bigger then i thought it would be2…does not hold a memory of what you are logging and will lose everything if you lose power for even 2 seconds3…does NOT have peak hold. it would be nice to see what something draws at start up like when the compressor kicks in on a A/C or freezer. this would be nice for the people wanting to figure out solar set ups so they dont over load inverters as you cant find the massive start up spikes UNLESS you sit and read it as something turns onconclusion….i have dropped my power bill with this. after finding out about the cable boxes i put them on power strips with main switches on them. turning them off when not in use, dropped my power bill 80 dollars a month where i live(we have crazy costs per-KW hour). other then my little problem with the timer resetting every 24 hours this thing has paid for itself already and was worth every penny, even if i have to wait 5 minutes for my cable boxes to reboot every time i watch TV.

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    Dan G

    I love these devices! I currently have 4, two in place in front of UPS’s that keep my server & network equipment up and my personal desktop up. I leave these units in to track my network & computing power consumption. The other two I’ve been using around the house. I plug in a device, leave it for a few days, and it gives me useful metrics on the total consumption over that time, and instantaneous amp or watt draw. Armed with these devices and a spreadsheet, I’ve indexed every electrical socket in my house and built out documentation and calculations. I now understand what devices draw power when they’re NOT in use, and I even have projections on what my future expenses will be under normal usage, minimal usage, and forgetting to turn things off all year usage 🙂 If you’re a techie and like getting involved, this is a FANTASTIC tool!

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