Standby power cost calculator
The little red lights, the clocks and the chargers that never leave the socket: list them and see what waiting costs over a year.
Standby costs you
$4.97 a year
29.3 kWh from 7 devices drawing 3.5 W in total
- Per month
- $0.41
- Per day
- $0.0136
- Over 10 years
- $49.73
| Device | Draw | Energy a year | Cost a year |
|---|---|---|---|
| TV on standby | 0.5 W | 3.65 kWh | $0.62 |
| Microwave clock | 0.5 W | 4.34 kWh | $0.74 |
| Coffee machine | 0.5 W | 4.29 kWh | $0.73 |
| Printer | 0.5 W | 4.38 kWh | $0.74 |
| Sound bar | 0.5 W | 3.83 kWh | $0.65 |
| Chargers left plugged in × 2 | 1 W | 8.76 kWh | $1.49 |
| Total | 3.5 W | 29.3 kWh | $4.97 |
Estimates from the figures you enter: not a bill, and not financial advice.
Small loads, all year round
Many devices keep drawing power while they look switched off: to listen for a remote, keep a clock, stay connected or simply because of their design. The Standby Power project at Lawrence Berkeley National Laboratory says most products now draw less than half a watt in standby, but a home has many of them, and together they come to 5–10% of residential electricity use.
List your devices with their standby watts, the hours a day they spend waiting and how many you have. Add rows for anything with a remote, a clock or a glowing light.
kWh a year = standby watts × hours a day × 365 × how many ÷ 1,000
Sources
- Lawrence Berkeley National Laboratory, Standby Power: most products draw less than 0.5 W in standby; together standby amounts to 5–10% of residential electricity use.
Questions
Is it worth unplugging everything?
Rarely for a single small device. Look for the ones that draw several watts around the clock, such as older equipment and devices that stay connected to the network, and put groups that are off together on a switched power strip.
How do I measure standby power?
Plug the device into a plug-in energy meter, switch it off or let it go idle, and read the watts after a minute. Very small draws can be below what a simple meter can show.
Does a charger use power with nothing attached?
A little. It is usually tiny, but it runs every hour the charger stays in the socket, so the yearly total is what counts.