Standby Power Cost Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/8/2026
The annual cost of standby power is calculated with standby power (W) × number of devices × 24 h × 365 days ÷ 1,000 × price per kWh. For 8 devices at 5 W of standby power each, at the regulated rate (€0.2001/kWh), the annual standby bill reaches about €70.
Explanation
Many electronic devices keep consuming electricity even once 'switched off', as long as they remain plugged into an outlet: internet routers, televisions, game consoles, chargers left plugged in, microwave ovens displaying the time... This residual consumption, sometimes called 'phantom load' or 'vampire power', runs continuously 24 hours a day, unlike a device's active use, limited to a few hours per day. This is the key difference from our electricity consumption calculator, which calculates the cost of active use over a chosen number of hours: here, the calculation assumes the device stays plugged in without interruption all year. Taken alone, the standby power of a single device (often between 1 and 10 W) seems negligible, but added up across several devices and over 8,760 hours a year (24 × 365), the cumulative cost can represent a significant share of a household's electricity bill — France's ecological transition agency (ADEME) regularly estimates this consumption at several dozen euros per year per household. The simplest solutions remain switched power strips, which physically cut power to several devices with a single action, or unplugging chargers and rarely used small devices. To calculate the cost of a device's active use rather than its standby, see our electricity consumption calculator; to compare an LED bulb with a traditional bulb, our LED bulb savings calculator.
Example: 8 devices at 5 W of standby power, price per kWh at €0.2001
Inputs
Standby power: 5 W per device. Number of devices: 8. Price per kWh: €0.2001.
Calculation
Annual consumption = 5 × 8 × 24 × 365 ÷ 1,000 = 350.4 kWh. Annual cost = 350.4 × 0.2001 ≈ €70.12.
Result
Standby power for these 8 devices costs about €70.12 per year.
Frequently asked questions
How do I find the actual standby power of my devices?
The most reliable method is a power meter (or a connected power strip with consumption monitoring), plugged in between the wall outlet and the device, showing its instantaneous consumption, including on standby. Failing that, the energy label or the manufacturer's technical sheet sometimes indicates a typical standby power, but it may differ slightly from the actual measured consumption.
Do all electronic devices consume the same amount on standby?
No, standby power varies enormously depending on the device and its age: an internet router or a TV set-top box, which must stay connected at all times, often consume more on standby (5 to 15 W) than a recent television (often less than 1 W on standby thanks to European ecodesign standards). Older devices, not subject to these standards, are generally the most energy-hungry on standby.
Is it always safe to cut power to a device?
For most everyday devices (television, console, charger), yes. However, be careful with certain equipment that needs to stay powered at all times to work properly (an internet router if you need a continuous connection, certain alarm or security systems, a scheduled recorder): check on a case-by-case basis before systematically unplugging everything.