Do smart plugs save money? Sometimes — but usually less than the marketing implies, and only if you actually use them to change behavior. The honest answer is that a smart plug saves money in two ways: by cutting standby (“phantom”) power on devices you’d otherwise leave on, and by giving you energy data that helps you kill bigger waste elsewhere. The plug itself uses a trickle of electricity, so the saving has to beat that first. This guide does the real math so you can decide whether the payback is worth it for your home.
We’ll base the numbers on published device specs, typical 2026 electricity prices, and standard standby-power figures — no invented statistics. Your mileage will vary with your tariff and habits, so treat these as worked examples, not promises.
The short answer
A smart plug pays for itself when you use it to switch off something that (a) draws meaningful standby power and (b) you’d genuinely have left plugged in and idle. That’s a real but narrow win. For most single devices, the annual saving is a few dollars or pounds — enough to pay back a $12 plug over a year or two, not enough to transform your bill.
The larger, underrated benefit is energy monitoring: a plug that shows real watts helps you find the appliances actually costing you money, so you can change how you use the big stuff. That insight often saves more than the plug’s own switching ever will.
What is standby power (and why it matters)
Standby or “phantom” power is the electricity a device draws while switched off or idle but still plugged in — the glow of a TV waiting for its remote, a games console in rest mode, a charger left in the wall, a microwave running its clock. Individually these loads are small, typically 0.5 to 15 watts each. Collectively, across a whole home, studies have long estimated standby load at somewhere around 5-10% of a household’s electricity use.
A smart plug attacks this by cutting power completely — either on a schedule (everything off overnight) or when you’re away. The saving depends entirely on how much standby power the device draws and how many hours you eliminate.
The actual math
Here’s the formula, kept simple:
Annual saving = standby watts ÷ 1,000 × hours eliminated per year × price per kWh
Let’s use a 2026-typical electricity price of around $0.17 / £0.27 per kWh (US average vs UK average; substitute your own tariff).
Example 1: an old set-top box drawing 15W
Say a cable box or older AV receiver pulls 15W in standby, and you cut it for 12 hours a day (overnight and while at work) — about 4,380 hours a year.
- 15W ÷ 1,000 = 0.015 kW
- 0.015 × 4,380 hours = 65.7 kWh/year
- 65.7 × $0.17 = ~$11/year (65.7 × £0.27 = ~£18/year)
That’s a real saving — enough to pay back a smart plug in a year (US) or a few months (UK), then keep saving.
Example 2: a modern TV drawing 0.5W in standby
Modern devices are far more efficient. A 2026 TV might sip just 0.5W in standby.
- 0.5W ÷ 1,000 = 0.0005 kW
- 0.0005 × 4,380 hours = 2.19 kWh/year
- 2.19 × $0.17 = ~$0.37/year (2.19 × £0.27 = ~£0.59/year)
Here the saving is trivial — you’ll never recoup the plug. Worse, the plug itself may draw as much as the TV’s standby, cancelling the benefit entirely.
Example 3: the plug’s own consumption
A Wi-Fi smart plug typically draws around 0.5 to 1W continuously to keep its radio alive. Over a year:
- 1W × 8,760 hours = 8.76 kWh
- 8.76 × $0.17 = ~$1.49/year (8.76 × £0.27 = ~£2.37/year)
So every plug has a running cost of roughly $1.50 / £2.40 a year. The device you’re controlling must waste more than that in avoided standby for the plug to come out ahead.
Where smart plugs genuinely save money
Based on the math, savings concentrate in a few places:
- Old, inefficient electronics. Pre-2015 AV gear, older set-top boxes, second fridges, and desktop PCs with power-hungry standby. These are the classic wins.
- Heaters and always-on appliances you forget. A space heater or towel rail left on all day is a large, obvious saving — a smart plug scheduling it off is worth far more than any standby trick.
- “Whole cluster” switching. One plug on a power strip feeding a TV, console, soundbar, and streaming stick cuts the combined standby of all of them at once — the loads add up.
- Charging that lingers. Devices left charging long after they’re full still draw a little; scheduling the charger off helps, modestly.
Where they don’t (be honest with yourself)
- Modern, efficient single devices. As Example 2 showed, a current TV or laptop charger in standby costs pennies. A plug won’t pay back.
- Anything you’d never actually unplug. If you’ll still want the device instantly available (a router, a smart speaker, the fridge), a plug that switches it off saves nothing because you won’t use it that way.
- Convenience-only setups. Buying plugs purely for “turn the lamp on with my voice” is fine — just don’t expect them to lower your bill.
The bigger win: energy monitoring
The most valuable money-saving feature isn’t switching — it’s measuring. A smart plug with energy monitoring (like the TP-Link Tapo P110 or Kasa EP25 in our Best Smart Plugs 2026: Cheapest Way Into Home Automation guide) shows you the real watts and running cost of any appliance. That data changes decisions:
- You discover your old chest freezer costs three times what a new one would, and finally replace it.
- You see a “quick” tumble-dryer cycle actually uses more than you assumed and shift to line-drying.
- You spot a device drawing 40W in “standby” that you thought was off.
None of those savings come from the plug’s switch — they come from the insight. That’s often where a smart plug pays for itself many times over, because it changes behavior around the appliances that dominate your bill.
The verdict on payback
Add it up and the honest conclusion is:
- A single plug on a genuinely wasteful device: pays back in 1-2 years, then saves a little each year.
- A plug on a modern efficient device: never pays back — the plug’s own draw eats the saving.
- A plug used for energy monitoring that changes a big habit: can save far more than it costs, indirectly.
So “do smart plugs save money?” Yes, if you deploy them where waste is real, and especially if you use monitoring to attack your big loads. No, if you scatter them on efficient gadgets and expect the switching alone to cut your bill. They’re a smart tool, not a magic one — which is also why they’re the cheapest, lowest-risk entry into home automation. If you’re weighing them against smart lighting, our Best Smart Light Bulbs 2026: Philips Hue & Alternatives guide covers that route.
FAQ: do smart plugs save money?
Do smart plugs use electricity themselves?
Yes, a small amount — typically 0.5 to 1 watt continuously to keep the Wi-Fi radio alive, costing roughly $1.50 / £2.40 a year per plug. The device you control has to waste more than that in avoided standby power for the plug to come out ahead, which is why they suit inefficient devices, not modern efficient ones.
How much can a smart plug realistically save per year?
On a genuinely wasteful device (an old AV box, a second fridge, a forgotten heater), realistically a few to a few tens of dollars or pounds a year each. On a modern efficient device, essentially nothing. The bigger savings usually come indirectly, from energy monitoring revealing which appliances to use less or replace.
Are smart plugs with energy monitoring worth the extra cost?
For most people, yes. The monitoring feature is where the real value lives — it shows you what appliances actually cost to run, which helps you cut the big loads that dominate your bill. The price premium over a non-monitoring plug is small, and the insight often pays for itself.
Will a smart plug save money on my TV or laptop?
Almost certainly not enough to matter. Modern TVs and laptop chargers draw very little in standby — often less than the plug itself uses. Buy a plug for those devices for convenience or scheduling, not to save money.
What’s the single best money-saving use of a smart plug?
Switching off a high-power appliance you tend to leave running — a space heater, towel rail, or a whole entertainment cluster on one strip — on an automatic schedule. That eliminates large, real waste. Pairing that with an energy-monitoring plug to find your worst offenders is the most effective approach.
Do smart plugs help with time-of-use electricity tariffs?
Yes, meaningfully. If your tariff charges less at off-peak times, scheduling a plug to run devices (like charging or a dishwasher on a timer socket) during cheap hours can save more than standby tricks ever will. Combined with energy monitoring, this is one of the strongest money-saving uses in 2026.
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