Standby Power Cost Calculator

About this calculator

Standby power (also called phantom load or vampire power) is the electricity a device draws while switched off or idle — think TVs, chargers, game consoles, and set-top boxes still sipping power from the wall. The annual cost is standby wattage ÷ 1000 × 24 hours × 365 days × electricity rate, converting continuous watt draw into yearly kilowatt-hours and then dollars (or your local currency).

Individually small, standby loads add up across a household's many always-plugged-in devices, and studies have found phantom power can account for 5-10% of residential electricity use. Homeowners and energy auditors use this calculation to quantify exactly how much a given device costs to leave plugged in, and to prioritize which ones are worth switching off at the outlet or replacing with lower-standby models.