Is a smart plug still worth it if it uses power itself?

In most cases yes, because the thing it switches off usually draws more than the plug does. A game console left in standby, an older TV, a printer, a coffee maker with a clock, a garage refrigerator running when nothing is in it — each can sit well above one watt around the clock. If the plug kills five watts of standby to spend one on itself, it is ahead. Where it does not pay is on a device that already draws essentially nothing when off, such as a modern lamp with a mechanical switch.

Does a Zigbee or Z-Wave plug use less than a Wi-Fi one?

Generally yes. A Wi-Fi radio has to keep an association with your access point alive and wake regularly to check for traffic, while low-power mesh radios such as Zigbee, Z-Wave and Thread wake briefly and transmit far less. In practice mesh plugs tend to sit at the low end of the range and Wi-Fi plugs at the high end, though the difference is fractions of a watt and is only meaningful across a large number of plugs.

Do smart plugs with energy monitoring use more power?

Slightly. The metering chip and the extra reporting traffic add a small amount, and monitoring plugs tend to sit at the upper end of the standby range. It is a reasonable trade, because the monitoring is what lets you find the appliances actually worth switching off. Once you have measured a circuit for a month and learned what it draws, you know whether the plug is earning its keep on that device or should be moved to a hungrier one.

Should I unplug smart plugs I am not using?

Yes, if a plug is sitting idle with nothing connected it is spending power for no reason, and a drawer of forgotten smart plugs is a small but permanent load. It is also worth removing them from the app so they stop generating failed-connection retries. If you are keeping a plug in place seasonally, such as one used only for holiday lights, unplugging it between seasons saves a few kilowatt-hours and avoids the plug going stale in your app.

Does the plug keep drawing power during an internet outage?

Yes, and often a little more. With no route to the cloud the Wi-Fi radio keeps retrying its connection, which can slightly raise the idle draw rather than lower it. The switching relay itself is unaffected — most plugs retain their last state and their local schedules through an outage — but the radio does not sleep just because there is nothing to talk to. That behavior is also the usual cause of the connection problems covered in why a smart plug keeps going offline.

Do Smart Plugs Use Electricity When Off? (About 1 Watt)

Written & researched by Derek Holt Home & Appliances Editor

Updated September 2026

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Yes. A smart plug draws roughly 0.5 to 1 watt continuously, even when the outlet it controls is switched off. The radio, the microcontroller and the small power supply inside never sleep, because the plug has to stay reachable to receive an on command. One watt running around the clock is about 8.8 kilowatt-hours a year, which at the US average residential price of roughly 17 cents per kWh reported by the Energy Information Administration comes to about $1.50 per plug per year. Most plugs pay that back easily by killing larger standby loads.

How much does that actually cost a year?

The arithmetic is simple and worth doing before you install ten of them. Annual kilowatt-hours equal watts multiplied by 8.76. Multiply that by your own rate, which you will find on your utility bill and which varies enormously by state — from around 11 cents per kWh in parts of the South to over 30 cents in Hawaii and California, on EIA figures as of 2026.

Standby draw	Per year	At 12 cents	At 17 cents	At 30 cents
0.3 W (low-power mesh)	2.6 kWh	$0.32	$0.45	$0.79
0.5 W	4.4 kWh	$0.53	$0.74	$1.31
1.0 W (typical Wi-Fi)	8.8 kWh	$1.05	$1.49	$2.63
1.5 W (Wi-Fi with metering)	13.1 kWh	$1.58	$2.23	$3.94
Ten plugs at 1.0 W	88 kWh	$10.51	$14.89	$26.28

So a single plug is trivial, and a house full of them is a real if modest line item — comparable to leaving one LED bulb on permanently.

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When does a smart plug save more than it costs?

Whenever the device it controls draws more in standby than the plug does. That is a low bar for a surprising number of appliances. The US Department of Energy has long estimated that always-on standby loads account for a meaningful share of residential electricity use, and the biggest offenders in a typical home are easy to name.

Game consoles in instant-on mode — historically several watts to well over ten, and the single best candidate for a smart plug.
Older televisions and soundbars — often a few watts each; modern sets are much better.
Printers — an inkjet left on can idle at several watts and periodically wake to clean its heads.
Cable and satellite boxes — among the worst offenders, though many cannot be power-cycled without a long reboot.
Second refrigerators and beer fridges — not standby, but the classic case where scheduling or switching off entirely saves real money.
Space heaters and window air conditioners — worth scheduling, but check the wattage limits first. Plug them directly into the wall rather than an extension cord, and keep one heat-producing appliance per outlet.

What is not worth it: a table lamp with an LED bulb and a switch, a phone charger with nothing plugged in, or anything you already unplug. Adding a one-watt plug to save nothing is a net loss.

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How do you keep the standby draw as low as possible?

Three practical moves. Choose Zigbee, Z-Wave or Matter over Thread plugs where you are installing several, since low-power radios sit at the bottom of the range. Skip energy monitoring on plugs where you do not need the data, because the metering chip adds a little. And unplug the ones doing nothing — a drawer full of powered-but-idle plugs is pure waste.

If your goal is measurement rather than switching, a monitoring plug is worth its slightly higher draw for a month or two on each suspect appliance, then move it on. The plugs owners rate most highly for accurate metering and reliable scheduling are in our smart plug picks, and the practical uses are set out in what you can do with a smart plug.

We never buy, install or physically handle the products we rank. Every recommendation comes from aggregated owner reviews, star ratings, review volume and published expert consensus — see how we rank.

Do Smart Plugs Use Electricity When Off?

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How much does that actually cost a year?

When does a smart plug save more than it costs?

How do you keep the standby draw as low as possible?

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