--- product_id: 1325926 title: "P4400 Kill A Watt Electricity Usage Monitor" price: "¥10213" currency: JPY in_stock: true reviews_count: 13 url: https://www.desertcart.jp/products/1325926-p4400-kill-a-watt-electricity-usage-monitor store_origin: JP region: Japan --- # 15A max current capacity 4 time-frame monitoring modes 0.2% - 2.0% measurement accuracy P4400 Kill A Watt Electricity Usage Monitor **Price:** ¥10213 **Availability:** ✅ In Stock ## Summary > ⚡ Take control of your energy — because every watt counts! ## Quick Answers - **What is this?** P4400 Kill A Watt Electricity Usage Monitor - **How much does it cost?** ¥10213 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/1325926-p4400-kill-a-watt-electricity-usage-monitor) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Instant Cost Calculator:** Estimate your electric bill before it arrives and avoid surprise expenses. - • **Precision Power Tracking:** Monitor volts, amps & watts with up to 0.2% accuracy for data-driven energy decisions. - • **Compact & Portable Design:** Easy-to-read LCD and plug-in setup lets you audit any appliance anytime, anywhere. - • **Power Quality Diagnostics:** Detect voltage drops and line frequency issues to safeguard your home’s electrical health. - • **Multi-Period Usage Insights:** Analyze your electricity consumption by day, week, month, or year to spot costly habits. ## Overview The P3 P4400 Kill A Watt Electricity Usage Monitor is a compact, highly accurate device designed to measure electrical consumption and power quality of 115V AC appliances up to 15 amps. Featuring a large LCD display, it tracks usage over customizable periods (day, week, month, year) and calculates estimated electricity costs. It also monitors voltage, current, and line frequency, helping users identify energy-wasting devices and optimize their power usage to reduce bills. ## Description desertcart.com 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 SpecificationsAccuracy: +/- 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 Product Description Ever wonder just how much electricity your indoor garden consumes? How much "juice" you pour in to growing every day or longer amount of time? Now, with Hydrofarm's Kill-a-Watt electricity usage monitor, you're always in the know. Choose from the Kill-a-Watt's four settings to monitor your electrical usage by day, week, month, or year. Find out just how much that holiday lighting setup really costs you, or use it as a judgement call on whether it's time to replace old equipment that becomes a drag on your finances. With an easy-to-read screen. Review: Accurate, Simple, and Addictively Useful - Accurate, Simple, and Addictively Useful The P3 Kill A Watt Electricity Usage Monitor is one of those inexpensive gadgets that quietly changes how you think about energy use. I first bought it to see how much power my old refrigerator was pulling—and ended up testing every appliance in the house. Setup is instant: plug it into the wall, connect any device, and the bright LCD display immediately shows volts, amps, and watts in real time. Leave it running for hours or days, and it totals up the kilowatt-hours (kWh), letting you see exactly what that appliance costs you per day or month. What makes it so helpful is how accurate and intuitive it is. You don’t need to be an engineer—just read the wattage and multiply by your utility rate. I found a few “phantom” power hogs drawing 10–20 watts even when off (like a cable box and an older UPS). It’s also great for testing PC builds, aquarium setups, or any electronics to ensure your power supply is sufficient. The build quality is solid, and the display remains easy to read even after years of use. The only caution: it’s designed for 115V North American outlets only—not for international use. Bottom line: A must-have tool for anyone curious about energy use or looking to cut electric bills. Simple, accurate, and surprisingly enlightening—it pays for itself quickly. Review: Terrific tool to understand your electronics power consumption - The P3 P4400 Kill A Watt Electricity Usage Monitor is an absolute essential tool that has easily proven its worth over years of diverse technical projects. While it was originally purchased to meticulously track power draws and ensure stability for a cryptomining system, its utility expanded far beyond that initial setup. Over the years, it has transformed into an indispensable diagnostic device for testing household appliances, auditing general electronics, and evaluating solar consumption and battery backup limits. The brilliance of the P4400 lies in its straightforward, no-nonsense design. By simply plugging an appliance directly into the unit, the clear LCD screen immediately reveals critical real-time electrical metrics including voltage, current, true wattage, frequency, and power factor. This level of precise monitoring takes the guesswork out of energy management, allowing you to see exactly how much cumulative kilowatt-hour (kWh) consumption a device is drawing over a specific duration. Beyond crypto rigs, its long-term versatility shines when mapping out off-grid energy storage or checking real-world solar generation loads. Before connecting sensitive electronics to a portable power station or calculating inverter thresholds, plugging devices into the Kill A Watt ensures you never exceed maximum capacity limits. It provides exact, empirical data rather than relying on manufacturer estimates, safeguarding backup setups against unexpected surges or overloads. Ultimately, the Kill A Watt P4400 is a rugged, reliable, and timeless diagnostic instrument that belongs in every tech enthusiast's toolkit. Its ability to adapt from high-intensity mining audits to everyday DIY power management underscores its enduring value. For anyone serious about understanding their electrical ecosystem, measuring device efficiency, or stress-testing backup battery thresholds, this meter remains a five-star recommendation. ## Features - 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 ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B00009MDBU | | Amperage Capacity | 15 A | | Batteries | 1 CR123A batteries required. | | Best Sellers Rank | #28,869 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #5 in Electrical Meter Sockets | | Certification | No | | Color | No Color | | Customer Reviews | 4.6 4.6 out of 5 stars (9,757) | | Date First Available | September 9, 2004 | | Display Style | LCD | | Included Components | usage monitor | | Item Package Quantity | 1 | | Item Weight | 6.4 ounces | | Item model number | LGP4400 | | Manufacturer | P3 | | Material | Other | | Number Of Pieces | 1 | | Part Number | P4400 | | Pattern | Monitor | | Power Source | air-powered | | Product Dimensions | 8.4 x 2.1 x 6.1 inches | | Size | Original version | | Special Features | Portable | | Style | 1 Pack - Model P4400 | | Usage | personal | | Voltage | 115 volts | | Warranty Description | 1 Year Limited | ## Product Details - **Brand:** P3 - **Color:** No Color - **Item Weight:** 0.4 Pounds - **Power Source:** Air-powered - **Style:** 1 Pack - Model P4400 ## Images ![P4400 Kill A Watt Electricity Usage Monitor - Image 1](https://m.media-amazon.com/images/I/61FOAk4UA5L.jpg) ![P4400 Kill A Watt Electricity Usage Monitor - Image 2](https://m.media-amazon.com/images/I/81iNu+VOrXL.jpg) ![P4400 Kill A Watt Electricity Usage Monitor - Image 3](https://m.media-amazon.com/images/I/51oVrphFwTL.jpg) ![P4400 Kill A Watt Electricity Usage Monitor - Image 4](https://m.media-amazon.com/images/I/91XZByzE2rL.jpg) ![P4400 Kill A Watt Electricity Usage Monitor - Image 5](https://m.media-amazon.com/images/I/61XZGr66kdL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: what is the difference between the p4400 and the p4460?** A: This device, the P4400, will reset all of its timed measurement values to zero if power is lost or the device is unplugged. The P4460 has "non volatile" memory, using a battery to provide the necessary voltage to power the (S)RAM memory, which means that it will not lose the data if power to the 4460 is lost. The P4460 also will let you input the cost per KWH from your provider to calculate the cost to operate the appliance over a week, month and year (assuming that your use is the same during the extrapolated period as it was during the measurement period). For me the data retention feature is well worth the extra $4 since I want to keep track of the energy used by a window air conditioner which will vary by the outdoor temperature, the sun hitting the building, the humidity, etc. **Q: .most of my outlets are 20 amps or more, the killawatt is only 15 amps does that make a difference in calculations, the garage is 40 amp.** A: This will only plug into a 120 VAC outlet. The standard 120 VAC outlet in almost all homes is only rated 15A continuous duty, but can take more for a second like when a room air conditioner compressor starts up. This is probably following those same rules. If the wiring is 12 gauge or thicker, it can be hooked to a 20 amp breaker even though all of the outlets in the average house are rated 15A, at least in most states. The reality of the matter is that wiring and outlets can always take somewhat more than the ratings and everything is oversized for safety. But is is always considered unsafe to plug in any device that uses more than 15 amps into a typical house outlet. An exception is commercial outlets that fit both home devices and heavier duty commercial device plugs and those outlets are usually rated at 20 amp. Those outlets are more common in businesses and uncommon in homes. An air conditioner or commercial refrigerator that uses more than about 10 continuous amps will normally be a 240 volt appliance and require different type of outlet designed for 240 volts, same is true of typical electric clothes dryer and this device would not adapt to those. **Q: Will this work with two prong (non-grounded) outlets?** A: Be Careful- defeating a polarized plug can be dangerous. The wide prong is neutral and connected to ground. The narrow prong is "hot" (energized) compared to ground. Some devices such as tools, chargers, and others use polarization to reduce the chance of electrical shock. If the device, such as most lamps, doesn't have a polarized plug then there is no concern, an adapter or extension cord is fine. If a device has a polarized 2 prong plug and you decide to use an adapter anyway, make sure the KillaWatt's plug's small slot on front is aligned with the wall plugs small slot and the larger slot on front aligns with the larger slot on the wall plug to maintain polarity. It is impossible to reliably maintain polarity using an extension cord so I would never attempt it. I would never cut off the ground prong, the blade prongs on the KillaWatt are the same size because the ground prong aligns the correct prongs with the wall plug so they do not need to be different sizes. Once you cut off the ground prong the odds are 50/50 of dangerously reversing the polarity of the plug on the front of the KillaWatt since it may, or may not, be plugged in correctly. Similarly if the wall plug slots are both the same size you are once again at 50/50 odds of plugging the KillaWatt in incorrectly with an adapter making the KillaWatt itself an "adapter" permitting you to plug polarized plugs into unpolarized wall plugs. Once again if the lamp etc doesn't have a polarized plug this is not an issue. (If you want to know more about why polarization makes things safer just ask) **Q: Hi, is this unit able to capture peak current draw? I want to see if my audio amplifier ever gets close to tripping my breaker.** A: I don't have it but from what I know about it is that you can measure watts for long period of time, So - reset meter, set it to continuously measure watt*hour (WH, watt for 1 hour=60 minutes*60=for 3600 seconds), connect your turned off amp, turn it on and immediately turn it off exactly after 1/2 second. Meter SHOULD show wattage consumed for 1/2 second because they say it measures power FEW TIMES PER Second (though still will be measuring after amp will be turned off, but it is ALMOST not consuming power) - that will be your surge power - multiply it by 3600 and by 2 (because 3600 for hour and for whole 1 sec it would be twice higher) and divide it on 115, or whatever voltage will be during measurements (put voltmeter to measure voltage, or just measure voltage before starting test, though voltage can can change fast). And you will get average current for first 1/2 sec. If you manage to turn it off exactly after 1/4 sec (but don't forget to multiply measured WattHour by 3600 and by 4, because 3600 higher for 1 hour and for whole 1 sec it would be 4 times higher) then measuring current surge will be more accurate. This calculation imitates WattHours consumed by amp as if it worked with average current equal to surge current for 1 hour, and that is why you divide those WattHours on voltage to get average current equal to surge current (which actually happened only during part of first second). So, if meter accurate enough to measure small power consumption then all this will work.But remember: amp MAY not like it, though SHOULD Tolerate such thing - anyway, don't blame me if something happens to it. I would do that myself, i believe this is not unusual for amp. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Accurate, Simple, and Addictively Useful *by E***S on October 20, 2025* Accurate, Simple, and Addictively Useful The P3 Kill A Watt Electricity Usage Monitor is one of those inexpensive gadgets that quietly changes how you think about energy use. I first bought it to see how much power my old refrigerator was pulling—and ended up testing every appliance in the house. Setup is instant: plug it into the wall, connect any device, and the bright LCD display immediately shows volts, amps, and watts in real time. Leave it running for hours or days, and it totals up the kilowatt-hours (kWh), letting you see exactly what that appliance costs you per day or month. What makes it so helpful is how accurate and intuitive it is. You don’t need to be an engineer—just read the wattage and multiply by your utility rate. I found a few “phantom” power hogs drawing 10–20 watts even when off (like a cable box and an older UPS). It’s also great for testing PC builds, aquarium setups, or any electronics to ensure your power supply is sufficient. The build quality is solid, and the display remains easy to read even after years of use. The only caution: it’s designed for 115V North American outlets only—not for international use. Bottom line: A must-have tool for anyone curious about energy use or looking to cut electric bills. Simple, accurate, and surprisingly enlightening—it pays for itself quickly. ### ⭐⭐⭐⭐⭐ Terrific tool to understand your electronics power consumption *by M***. on August 24, 2026* The P3 P4400 Kill A Watt Electricity Usage Monitor is an absolute essential tool that has easily proven its worth over years of diverse technical projects. While it was originally purchased to meticulously track power draws and ensure stability for a cryptomining system, its utility expanded far beyond that initial setup. Over the years, it has transformed into an indispensable diagnostic device for testing household appliances, auditing general electronics, and evaluating solar consumption and battery backup limits. The brilliance of the P4400 lies in its straightforward, no-nonsense design. By simply plugging an appliance directly into the unit, the clear LCD screen immediately reveals critical real-time electrical metrics including voltage, current, true wattage, frequency, and power factor. This level of precise monitoring takes the guesswork out of energy management, allowing you to see exactly how much cumulative kilowatt-hour (kWh) consumption a device is drawing over a specific duration. Beyond crypto rigs, its long-term versatility shines when mapping out off-grid energy storage or checking real-world solar generation loads. Before connecting sensitive electronics to a portable power station or calculating inverter thresholds, plugging devices into the Kill A Watt ensures you never exceed maximum capacity limits. It provides exact, empirical data rather than relying on manufacturer estimates, safeguarding backup setups against unexpected surges or overloads. Ultimately, the Kill A Watt P4400 is a rugged, reliable, and timeless diagnostic instrument that belongs in every tech enthusiast's toolkit. Its ability to adapt from high-intensity mining audits to everyday DIY power management underscores its enduring value. For anyone serious about understanding their electrical ecosystem, measuring device efficiency, or stress-testing backup battery thresholds, this meter remains a five-star recommendation. ### ⭐⭐⭐⭐⭐ Knowledge is Power: Manage Your Electric Bill the SMART and EASY Way *by O***K on May 11, 2015* Ever wonder how many watts an appliance is using? I have. That's why I bought this; I was wondering if my "tea machine" Tiger PDN-A50U Electric Water Dispenser, 5.0-Liter was an energy hog or a conservation appliance. Thanks to this, I now know it's an energy SAVER. This could not be easier to use. Simply plug the meter into any wall socket. Leave it there as long as you like and use this meter like an electrical outlet. When you want to measure an appliance's electricity use, you simply press the "Watt" button & the LCD display will show you the real-time wattage usage. For example, with my "tea machine," when it boils water, it uses about 900 watts. Once it stops boiling, it uses just .3 watts, on average, to keep warm. When dispensing, it uses 62 watts (to power an electric pump), then immediately reverts back to its .3 watt "keep warm" usage. This can also be used as a voltmeter (measuring the electricity flow INTO the outlet). For American household power, this is roughly around 120 volts (except in "brown out" conditions). Useful to check during brownout conditions, simply because using some appliances during low voltage conditions can potentially damage them (this, fortunately, rarely happens in the US, but some Californians have occasionally experienced this). There's also a purple KwH button. This will let you measure the KwH usage of an appliance over a period of time. If you have an appliance (say, like a stereo subwoofer) that you suspect might be a Vampire Power Energy Hog (one that uses a lot of power, even when turned off), you can easily confirm this suspicion by plugging it into this meter, pressing the KwH button, & then check in 24 hours and see how many KwH your appliance has consumed. If your subwoofer's an energy hog, just unplug it when you're not using it & you'll lower your electrical bills. I LOVE this device, because it's helped me logically evaluate actual energy usage, instead of just going by my "gut" feeling. Knowledge is Power! This is easy to use & well worth every penny of its cost. In just a month, it more than pays for itself, if you've not been paying sufficient attention to your energy use. Now, instead of guessing how much power you're actually using to operate an appliance, now you can know. Great for everything from rice cookers, tea machines, toaster ovens, computers, printers, stereo equipment, battery chargers & more. A+! ## Frequently Bought Together - P3 P4400 Kill A Watt Electricity Usage Monitor - Upgraded Watt Power Meter Plug Home Electrical Usage Monitor Consumption, Energy Voltage Amps Kill Tester with Backlight, Overload Protection, 7 Modes Display - Klein Tools RT250 GFCI Outlet Tester with LCD Display, Electric Voltage Tester for Standard 3-Wire 120V Electrical Receptacles --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/1325926-p4400-kill-a-watt-electricity-usage-monitor](https://www.desertcart.jp/products/1325926-p4400-kill-a-watt-electricity-usage-monitor) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-09-21*