Smart Home Power Draw Calculator
Add up the always-on power your smart home devices draw and see the yearly kWh and running cost — the phantom load of hubs, plugs, cameras and speakers adds up.
How it works
Total W = devices × watts each · Daily kWh = total W × hours ÷ 1000 · Yearly cost = daily kWh × 365 × rate
Smart-home gadgets each sip only a few watts, but they run 24/7 and there are often dozens of them, so the standby (phantom) load quietly accumulates on your bill. The total is device count times average draw, converted to kilowatt-hours over the hours they stay powered, then multiplied across the year and your electricity rate. Because it is always-on, even a small per-device figure becomes a real annual cost — which is why choosing efficient hubs and switching off devices that need not stay live actually matters.
Worked example
20 devices averaging 3 W each draw 60 W. Running 24 hours a day that is 1.44 kWh daily, or about 526 kWh a year; at $0.17/kWh that comes to roughly $89 a year just to keep the smart home idling.
Frequently asked questions
How much power do smart devices really use?
Individually very little — a smart plug or bulb in standby draws about 0.5–2 W, a hub or camera 2–5 W, a smart speaker 2–4 W idle. The issue is quantity and the fact they run continuously, so a device-heavy home can add tens of dollars a year in phantom load alone.
Do smart plugs save more than they cost to run?
Usually yes, if they switch off something meaningful. A smart plug drawing 1 W all year uses under 9 kWh, but if it lets you fully cut a TV or space heater that would otherwise idle, the savings dwarf the plug's own draw. On trivial loads, though, the plug can cost more than it saves.
Should I unplug smart devices to save energy?
Only the ones you rarely use — unplugging a hub or a device that automates your home defeats its purpose. The bigger wins are consolidating to fewer, more efficient devices and using them to eliminate larger standby loads elsewhere in the house.
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This calculator is for educational purposes. Double-check important results before acting on them.