Standby Power Cost Calculator
The electricity that devices draw while switched off or idle — the phantom load — from how many there are and what they draw, with the yearly cost, the share of a household's usage and what a smart plug or a switch would save.
A television, a games console, a router, chargers and a dozen other devices each draw a watt or several while doing nothing.
How the standby power cost calculator works
A television, a games console, a router, chargers and a dozen other devices each draw a watt or several while doing nothing. Count them, multiply by their average draw and the hours they sit idle, and the year's kilowatt-hours appear; a typical home wastes 5 to 10% of its electricity this way. Switching off at the wall, or a smart plug that does it on a schedule, recovers most of it.
Formula: kWh per year = devices × watts × hours per day × 365 / 1000; cost = kWh × tariff
Worked examples
| Inputs | Standby cost per year | Note |
|---|---|---|
| Fifteen devices at 3 W | 91.98 | about 330 kWh a year |
| A gadget-heavy home | 245.28 | a large phantom load |
| Efficient devices | 15.33 | not worth the bother |
FAQFrequently asked questions
What is standby power?
The electricity a device draws while off or idle — keeping a remote receiver, a clock, a network connection or a charger circuit alive. Also called phantom or vampire load.
How much does a device draw on standby?
Modern televisions and consoles under a watt in true standby but 10 to 20 in "instant on" modes; set-top boxes and routers 5 to 15 continuously; chargers under half a watt. Three watts is a fair average across a home.
Is it really worth switching off?
For a few large offenders — the console, the set-top box, the old amplifier — yes. For chargers and modern appliances, no. A power meter for a day finds the culprits.
Do smart plugs use power too?
About a watt each. They pay for themselves only on devices drawing several watts, or on a strip that switches off a whole entertainment system.
What about appliances that must stay on?
The router, the fridge, anything with a security function. Count them as standby if you like, but they are not savings.
Where these figures come from
- International Energy Agency — Energy Efficiency — appliance consumption and standby power context
- Australian Energy Regulator — the Australian energy market regulator
Last checked: September 2026. Appliance power figures are typical ratings; check the label on your own equipment, which is authoritative for it.