How the cost is figured
Yearly kWh equals watts times idle hours per day, times 365, divided by 1,000. Cost equals kWh times your price per kWh. Every row uses the same formula, so the ranking shows which device is worth the effort.
Standby and leave-on cost map
Find the plug-in loads that quietly cost you money
List what is plugged in, how many watts each one draws, and how many hours it sits idle. The map ranks each device by yearly cost and gives a plain verdict: leave it on, or unplug it.
Your device worksheet
Check your bill. The default is an example value.
| Device | Watts | Hours/day idle | Remove |
|---|
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Reading the map
Idle does not mean off
Idle hours are the time a device draws power without doing its main job. A TV in standby, a game console that is off but still on the network, or a charger with no phone attached all count.
A quick example
A 12 watt set-top box idle for 20 hours a day uses about 88 kWh a year. At $0.16 per kWh, that is about $14. A 1 watt phone charger idle for 20 hours uses about 7 kWh, or roughly $1.14.
Common myths
"Plugged in means drawing power" is only partly true. Many chargers draw almost nothing with no load. The real cost sits in devices with clocks, lights, remotes, or network radios that never sleep.
Cutting the cost without buying anything new
Use what you already have
- Put TVs, speakers, and game consoles on one power strip with a switch. Turn the strip off at night.
- Set the console to a full power-off mode, not rest mode.
- Use the timer on an existing lamp or heater plug instead of leaving it on.
- Unplug a second fridge or chest freezer in a garage if it is not needed.
Seasonal patterns
- Summer: window units and dehumidifiers run more hours. Check their idle time too.
- Winter: space heaters left on standby or on low can add up fast.
- Holidays and travel: the whole house idles. Unplug entertainment gear and set the fridge to a sensible setting.
Typical idle watts (rough): cable or satellite box 10 to 20 W, game console in rest mode 5 to 15 W, TV in standby 0.5 to 3 W, microwave clock 2 to 5 W, laptop charger 0.1 to 0.5 W with nothing attached.