Standby Power by Device Calculator (Vampire Load Audit)

How it works

kWh per year = watts × 24 × 365 ÷ 1,000 = watts × 8.76 · cost = kWh × price · share = standby kWh ÷ annual kWh

Anything with a remote control, a clock, a network connection or an external power brick keeps drawing a little current when it is "off", and because it does so every hour of the year the arithmetic is unforgiving: one watt of continuous draw is 8.76 kilowatt-hours a year. Individually most devices are small, but a home has dozens, and a few — pay-TV boxes waiting for updates, consoles in instant-on mode, older adaptors — draw as much as a light bulb. Studies put standby at five to ten percent of residential electricity, concentrated in the entertainment corner, which is why a single switched strip there captures most of the saving while unplugging phone chargers achieves almost nothing.

Worked example

Two TVs, a set-top box, a console in rest mode, a sleeping PC, six chargers, three kitchen appliances with clocks and three always-on gadgets draw about 52 W of standby — around 450 kWh a year, $82 at $0.18/kWh and roughly 11% of a 4,000 kWh household. A switched strip on the TV corner alone would save about $43 of that.

Frequently asked questions