
P3 P4400 Kill A Watt Electricity Usage Monitor
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Purchase options and add-ons
- 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
Additional Details
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This product has sustainability features recognized by trusted certifications.Made with chemicals safer for human health and the environment.As certified by
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Global Recycled Standard (GRS) certified products contain recycled content that has been independently verified at each stage of the supply chain, from the source to the final product and meet social, environmental, and chemical requirements. The purchase of Global Recycled Standard (GRS) certified products supports the use of recycled content in the supply chain. A product must contain at least 50% certified GRS material to qualify for inclusion in Climate Pledge Friendly.Certification Body
IntertekCertification Number
TE-00327607Contains at least 50% recycled material.As certified by
Global Recycled Standard
Global Recycled Standard (GRS) certified products contain recycled content that has been independently verified at each stage of the supply chain, from the source to the final product and meet social, environmental, and chemical requirements. The purchase of Global Recycled Standard (GRS) certified products supports the use of recycled content in the supply chain. A product must contain at least 50% certified GRS material to qualify for inclusion in Climate Pledge Friendly.Certification Body
IntertekCertification Number
TE-00327607
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From the manufacturer
Electricity Usage Monitor
It's no secret that electricity bills are on the rise. With the P3 P4400 you can cut your energy costs and find out what appliances are actually worth keeping plugged in by finding power-wasting appliances. Simply connect any appliance to the Kill A Watt EZ, it will then assess how efficient each appliance really is.
Kill A Watt EZ Power Monitor
Calculate your homes cumulative electrical expenses and forecast 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 EZ you’ll know 'Watts' killing you.
User Friendly and Easy to Install
Save on Your Electricity Bills
Unique Features
- Easy to read large LCD screen
- Accurate within 0.2%
- Calculates cost and forecasts by week, month and year
- Displays eight critical unites of measurements
- Built in Battery Backup
Technical Specifications
Model: P4400
Operating Voltage: 115 VAC
Max Voltage: 125 VAC
Max Current: 15 A<
Max Power: 1875 VA
Weight: 5 oz
Dimensions: 5 1/8″ H x 2 3/8″ W x 1 5/8″ D
Kill A WATT EZ Power Monitor
Model P4400
With the P4460 you can easily identify which appliance in your home is costing you the most money. The Power Monitor also allows you to enter your Utility providers cost of electricity so you can monitor and pinpoint what each appliance is costing you.
Founded in 1987, P3 International is a privately owned manufacturer of solution oriented consumer products. For the last twenty five years we have strived to develop products that are easy to use and ahead of their time.
We 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 us we are always looking for innovative new products which we can offer our customers.
Product Description
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.
Amazon.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 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
Product information
Technical Details
| Manufacturer | P3 |
|---|---|
| Part Number | P4400 |
| Item Weight | 6.4 ounces |
| Product Dimensions | 8.4 x 2.1 x 6.1 inches |
| Item model number | LGP4400 |
| Batteries | 1 CR123A batteries required. |
| Is Discontinued By Manufacturer | No |
| Size | Original version |
| Color | No Color |
| Style | 1 Pack - Model P4400 |
| Material | Other |
| Pattern | Monitor |
| Power Source | air-powered |
| Voltage | 115 Volts |
| Amperage Capacity | 15 Amps |
| Item Package Quantity | 1 |
| Number Of Pieces | 1 |
| Display Style | LCD |
| Certification | No |
| Special Features | Portable |
| Usage | personal |
| Included Components | usage monitor |
| Batteries Included? | No |
| Batteries Required? | No |
| Warranty Description | 1 Year Limited |
Additional Information
| ASIN | B00009MDBU |
|---|---|
| Customer Reviews |
4.6 out of 5 stars |
| Date First Available | September 9, 2004 |
Warranty & Support
Feedback
WARNING:
Safety and product resources
Safety documents
Important information
Warranty does not cover misuse of product.
Customer reviews
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Top reviews from the United States
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- Reviewed in the United States on October 20, 2025Size: Original versionVerified PurchaseAccurate, 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.
- Reviewed in the United States on January 20, 2026Size: Original versionVerified PurchaseI purchased this product to keep an eye on my electrical usage of accessories, including heaters in my garage to make sure they are not overloading the system. Works as expected and quality made and seems to be very accurate.
- Reviewed in the United States on November 9, 2008Size: Original versionVerified PurchaseThis product works as expected. I purchased this unit to make an analisis about parasit power consumption in my electronic appliances in home.
I discover the following:
- the lcd requires 180 ~ 230 watts. After going to standby or shutdown, the tv use 60 watts for 3 minutes. This is to cool down the lcd lamp for protection (fans and additional circuit works for this time). Can be a mistake if I remove the AC cable power or enterely shutdown the tv without allow this process to finish. Good discover. After this 3 minutes, the standby mode on the monitor only requires 05. to 1w.
- my motorola cable system requires the same ammount of power (27 ~ 30 watts) no matter if this unit is ON or off!!!!... all the time is fully powered (because have an internal hard drive). But I believe (wrong!) this unit must save about 50% if is off.. but no!!!!
- the blackberry / sony ericson chargers do not drain any power (0W) from AC if the phone itself is not connected. I DON't need to disconect this chargers from the outlets.
- My APC Smart UPS 1500 drain 30 WATTS! even when is completely turned off!!!Is better to disconnect this unit from the ac cable!!! amazing!...
- My pc (dimension 9150) is a power hungry pc. Because have pentium D (first edition) who requires a lot of power. This pc requires 230 watts but when I play Command Conquer (3D real time strategy) and because I have a HD2900 ATI High Definition card who requires 650 watts PSU. Interesting: when I play the game the power rise from 230 to 300~320 watts!!!!
This unit is very usefull to understand how the electronic systems works and if are energy efficient and how you must manage this units to save power and money.
Highly recommended, is cheap and you can check your ac freq and exact voltage (i have 128 volts from 127 expected in the ac line)......
enjoy and sorry my english
- Reviewed in the United States on May 18, 2025Size: Original versionVerified PurchaseThe Kill A Watt Energy Monitor (I have the P4400) can be mighty useful for determining energy usage of plug-connected devices, especially ones with varying usage, such as refrigerators, plug-connected air conditioners, humidifiers and dehumidifiers, and perhaps computers.
I got mine in 2018, so it may not be quite the same as current models.
A few things could be improved:
• It would be mighty nice for the display to have a backlight. But, unlike some others, I have no problem reading it when shining a flashlight on it in a dark location.
• For some devices (e.g., a refrigerator), it can be mighty inconvenient to read without using at least one extension cord, which is a bit Mickey Mouse. A Kill A Watt Connect (https://www.amazon.com/dp/B0CVS4WXM9) might address this, but some have suggested the 32″ connecting cable is on the short side. I don’t have that model, so I can’t comment from experience.
• When plugged into the top outlet in a duplex receptacle, it blocks the lower receptacle. Again, a short extension cord could fix this.
• As several others have noted, the outlet receptacle is mighty tight. Not so tight as to be unusable, but much tighter than a normal receptacle—and it doesn’t have the same feel as a hospital-grade receptacle, which is also pretty snug.
• There is no battery backup, so acquired data are lost in a power failure. Power failures where I live are infrequent, so this isn’t a big deal for me. There are other models that do have battery backup.
This model doesn’t calculate energy cost (some others do), but this isn’t a big deal for me; I think it’s probably easier to just put the energy consumption data in a spreadsheet and figure the cost there.
There are some other brands that cost less and even have more features; I haven’t tried them so I can’t really comment. I haven’t felt the need for most of these features strongly enough to try another model.
Were it possible, I’d probably give the Kill A Watt a 4.5.
A Poor Man’s Clamp Meter?
For devices like a hair dryer or toaster that have relatively constant consumption when in use, I’m not sure it’s necessary to accumulate months of data unless one is a real fanatic—so a quick measurement will often suffice.
Though intended for monitoring energy use, the Kill A Watt is also an economical substitute for a clamp meter and line splitter. I have a hard time believing that it’s in the same league, but the specifications suggest otherwise—and the indicated values are very close to what I get with a Fluke 87 and i400 current clamp. For someone who’s not an electrician, the Kill A Watt may well be good enough, and it’s easier to use and less expensive. One big convenience: it’s easy to quickly switch between current and voltage under load at the press of a button, which is much harder to do with fancy meter.
The Kill A Watt also provides watts, VA, and power factor at the press of a button. Results can sometimes be surprising: I have one low-flicker LED bulb with a power factor of 0.7, while this isn’t great, I remind myself that the VA is still a lot less than that of an incandescent bulb with a unity power factor. And it’s interesting just to know this stuff.
For this purpose, the Kill A Watt seems better suited than some of the newer models with extra features that don’t really apply.
- Reviewed in the United States on February 12, 2026Size: Original versionVerified PurchaseWorks as expected. Just plugged the coffee machine into mine to see what the draw is when it's not running. Make sure you read the manual and set the $/kwh so it calculates it correctly for the cost in your area. It does take some time to come to equilibrium on that so leave it for a bit.
Top reviews from other countries
Patrick MontagueReviewed in the United Kingdom on November 22, 20221.0 out of 5 stars Non UK product
Size: Original versionVerified PurchaseIf you live in the UK, do NOT buy this product. It is not designed for the UK and you will have to return it. The company, so far, has refused to pay the return postage, even though this is entirely their mistake. I have no idea why it is not clearly labelled.
-
JorgeReviewed in Mexico on August 1, 20185.0 out of 5 stars Excelente producto.
Size: Original versionVerified PurchaseFantástica compra, cumplió todas mis expectativas y al tener un soporte de hasta 1.8kw me permite medir dispositivos de alto consumo.
Quien iba a decir que mi PC (solo el gabinete) consume 4 veces mas que mi refri de 7 pies. Gracias a esta maravilla, ahora lo sé.
Recomendadísimo, entrega en excelentes condiciones y vino empaquetado con su bolsa antigolpes.
PhilReviewed in Japan on January 19, 20211.0 out of 5 stars Shouldn't Be Sold In Japan
Size: Original versionVerified Purchase1. Operating voltage is incompatible with Japan's 100VAC.
2. Seller support is poor and maker (P3) doesn't respond to emailed questions.
A waste of money.
RodReviewed in the United Kingdom on August 25, 20211.0 out of 5 stars Not useable in UK
Size: Original versionVerified PurchaseBought this on Amazon UK and it does not state that it is not suitable for UK use - plugs are US(?). Will now have to pay a lot to return it to a US address. Not impressed.
-
Alvaro BecerraReviewed in Mexico on September 5, 20195.0 out of 5 stars Buen producto, muy preciso.
Size: Original versionVerified PurchaseBásico, pero es justo lo que necesitaba. Funciona perfecto.
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Product Summary: P3 P4400 Kill A Watt Electricity Usage Monitor
From P3
About this Item
- 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
Product Description
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
Newer Version Available
P3 International P4460 Kill A Watt EZ Electricity Usage Monitor , grey, 4.4 out of 5 stars, 3,890 ratings
Important Information
Bulb Voltage
115 volts
Proposition 65 Warning for California Consumers
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
- Small parts. Not for children under 3 yrs.
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