Smart-Home Power Cost Calculator
Enter a device’s wattage, how many hours a day it runs, and your electricity rate to see what it really costs to keep on — per day, per month, and per year.
The hidden cost of an always-on home
A smart home runs on a fleet of small, always-on devices — hubs, mesh nodes, cameras, plugs, speakers, a NAS — each sipping a handful of watts every hour of every day. Individually they look trivial; together they can rival a fridge. Putting a real number on the running cost is the first step to deciding what deserves to stay on and what can sleep.
Sizing new gear too? Pair this with the Battery Life Estimator for portable devices, or check your network load with the Internet Speed Needs tool.
Frequently Asked Questions
How do I find a device's wattage?
Check the label on the plug or power brick, the spec sheet, or the manual — it's usually printed as watts (W) or as volts and amps you multiply together. For always-on gear a cheap plug-in energy monitor gives a real reading, including the standby draw that nameplate figures miss. Smart hubs, mesh nodes, and cameras often pull only a few watts, but running 24/7 that still adds up over a year.
Why does a 5-watt gadget still cost money?
Because it never switches off. A device drawing 5 W around the clock uses about 43.8 kWh a year, so at typical rates it quietly costs a few dollars per device — and a smart home can have dozens of them. This calculator multiplies by your device count so you can see the whole standby load of the house at once, which is often the easy saving people overlook.
What electricity rate should I enter?
Use the per-kWh rate from your latest bill, including any delivery or supply charges rolled into the unit price, since that's what you actually pay for each kilowatt-hour. If your plan has time-of-use pricing, enter a blended average — or the peak rate for gear that mostly runs in the evening — to keep the estimate honest.
Are these figures exact?
No — treat them as a close estimate. Real consumption varies with standby cycling, firmware behaviour, and devices that spike when active and idle the rest of the time, and your bill also carries taxes and fixed charges this tool doesn't model. It's built to compare devices and spot the always-on costs worth cutting, not to reproduce your utility statement to the cent.
Estimates only, based on the figures you enter and an average 30.44-day month. Real bills depend on tariffs, standby draw, and how each device cycles. Not financial advice.