Standby Power Waste Calculator

Work out standby power waste instantly with clear inputs, formula shown and shareable results.

About Standby Power Waste Calculator

Standby power looks trivial per device but accumulates: twelve devices at 2.5 W for twenty hours a day is 219 kWh a year. Modern regulations cap standby at 0.5 W for most products, but set-top boxes, games consoles and older equipment remain well above that.

Formula

Standby waste

annual kWh = devices x standby watts x hours x 365 / 1000

Worked example

With the default values below, Standby Power Waste Calculator returns Annual standby cost of $61.32. Change any input above and every figure here is recalculated in your browser.

Inputs used

Devices left on standby: 12 devices
Average standby draw: 2.5 W
Hours on standby per day: 20 h/day
Electricity rate: 0.28

Results

Annual standby cost: $61.32
Annual energy wasted: 219.00 kWh
Total standby load: 30.00 W
Annual CO2: 46.0 kg

Step by step

1Values used
2Standby waste
3Annual standby cost= 61.32
4Annual energy wasted= 219.00 kWh
5Total standby load= 30.00 W
6Annual CO2= 46.0 kg

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Which devices are the worst offenders?

Set-top boxes and games consoles in rest mode can draw 10-20 W. Chargers and modern televisions are usually under 1 W.

Is switching off at the socket worth it?

For high-standby devices yes. For a phone charger drawing 0.1 W it saves about 25 pence a year, which is not worth the inconvenience.