As a rough guide, every 1 watt of standby power used continuously for a full year consumes about 8.76 kWh. Using an example electricity unit rate of 26.11p per kWh, that works out at about £2.29 per year for every 1W of constant standby load.

That means:

These figures are estimates. Your actual standby power cost depends on the appliance wattage, how long the device stays plugged in, your electricity tariff, your region and your payment method.

Quick answer: how much does standby power cost?

For one modern appliance, standby power often costs only a few pounds per year. The bigger issue is the total background load across the home.

A TV, microwave display, games console, smart speaker, set-top box, router and several chargers may each seem minor on their own. Together, they can create a continuous standby load that runs every hour of the year.

A simple way to estimate it is:

1W left on all year ≈ 8.76 kWh per year

At an example rate of 26.11p/kWh, that is about:

£2.29 per year for each continuous watt

So if your combined standby load is around 20W, the yearly cost would be roughly:

20 × £2.29 = £45.80 per year

This is not a guaranteed saving. It is a useful estimate for understanding scale.

What standby power actually means

Standby power is the electricity a device uses when it is not actively being used but is still plugged in and ready to respond.

Common examples include:

• a TV waiting for the remote control;
• a microwave keeping its clock display on;
• a games console in rest mode;
• a set-top box staying ready for updates;
• a smart speaker waiting for a voice command;
• a broadband router staying connected;
• chargers or adapters left plugged in.

Not all standby use is waste. Some devices need to stay on for safety, connectivity or updates. The aim is not to switch off everything. The aim is to identify avoidable background use.

How to calculate standby power cost

Use this formula:

Watts ÷ 1,000 × hours × electricity unit rate = cost

For a full year, the formula becomes:

Watts ÷ 1,000 × 8,760 × electricity unit rate = yearly cost

Where:

• watts means the standby power draw of the appliance;
• 1,000 converts watts into kilowatts;
• 8,760 is the number of hours in a year;
• unit rate is the price you pay per kWh of electricity.

For a more detailed calculation, compare your estimate with the standby power cost calculator and replace the example unit rate with your own tariff.

Example: 1W on standby all year

A device using 1W continuously would use:

1 ÷ 1,000 × 8,760 = 8.76 kWh per year

At 26.11p/kWh:

8.76 × £0.2611 = £2.29 per year

Example: 5W on standby all year

A device or group of devices using 5W continuously would use:

5 ÷ 1,000 × 8,760 = 43.8 kWh per year

At 26.11p/kWh:

43.8 × £0.2611 = £11.44 per year

Example: 20W combined standby load

Several devices adding up to 20W of standby power would use:

20 ÷ 1,000 × 8,760 = 175.2 kWh per year

At 26.11p/kWh:

175.2 × £0.2611 = £45.75 per year

This is why standby power is best treated as a whole-home background load rather than a single-device issue.

Standby power cost examples for common UK appliances

The figures below are example scenarios, not universal appliance ratings. Actual standby use varies by model, age, settings and whether the device has network features.

If you need accuracy, measure the device rather than relying on generic examples.

Why standby costs vary from home to home

Two homes can have very different standby costs.

The main reasons are:

• how many devices are plugged in;
• how old the appliances are;
• whether devices have displays, network features or rest modes;
• how often equipment is left on overnight;
• whether the home uses games consoles, TV boxes or smart speakers;
• the electricity unit rate;
• the region and payment method;
• whether the tariff is single-rate or multi-rate.

The standing charge is not caused by standby use. Standby power affects the unit-rate part of the bill because it adds kWh consumption.

Which devices are worth turning off?

Start with devices that are easy to switch off and do not need to stay connected.

Good candidates may include:

• TVs and entertainment systems not used overnight;
• games consoles left in rest mode;
• chargers when nothing is charging;
• microwave displays if the clock is not needed;
• spare monitors and desktop accessories;
• older audio equipment;
• devices in guest rooms or rarely used spaces.

A switched extension lead can help if several non-essential devices are grouped together.

When you should not switch a device off

Some devices should stay on for safety, food storage, medical reasons or essential connectivity.

If you are unsure, check the manufacturer guidance or supplier advice before switching something off regularly.

Can smart plugs help reduce standby costs?

Smart plugs can help in some situations, but they are not automatically the best answer.

They may be useful when:

• a socket is hard to reach;
• several devices can be controlled together;
• you want a schedule;
• the smart plug includes energy monitoring;
• you already know a device or group of devices is using noticeable standby power.

For readers who want to understand the monitoring side, this connects naturally to smart plug energy monitoring.

They may be less useful when:

• the appliance already uses very little standby power;
• the smart plug itself uses almost as much as it saves;
• the device should stay on for safety or connectivity;
• the setup becomes more complicated than simply switching something off.

A sensible rule is:

Measure first, then decide.

If you are considering a smart plug mainly for standby use, compare the cost of the plug with the standby load you are trying to control before deciding whether it is worth it for your home.

How to check your own standby power use

There are three practical ways to check standby power.

1. Look for the appliance specification

Some manuals and manufacturer websites list standby use. Look for terms such as:

• standby power;
• off mode;
• sleep mode;
• networked standby;
• power consumption.

2. Use a plug-in energy meter

A plug-in energy meter can show how many watts a device uses while idle or in standby. This is often the clearest way to check older appliances, entertainment equipment and small devices.

3. Use smart meter readings carefully

A smart meter can show whole-home electricity use, but it may not isolate one appliance. You can still use it to understand your background load by switching off non-essential devices and watching whether the reading changes.

Do not switch off essential devices for testing.

How to reduce standby power without making life difficult

You do not need to unplug everything in the house.

Start with simple habits:

• switch off entertainment devices overnight if they do not need to stay on;
• unplug chargers when nothing is charging;
• use switched extension leads for groups of non-essential devices;
• check console rest mode settings;
• avoid leaving rarely used appliances on permanently;
• measure high-suspicion devices before buying extra equipment.

The best approach is practical, not extreme. Remove avoidable standby use where it is easy, safe and worthwhile.

Should you worry about standby power?

Standby power is usually not the largest part of a UK electricity bill. Heating, cooking, laundry, hot water, refrigeration and high-power appliances often matter more.

But standby power is still worth understanding because it is easy to estimate and often easy to reduce.

If your combined standby load is only a few watts, the cost may be modest. If several devices are drawing power continuously, the cost can become more noticeable over a full year.

To understand this in the wider household context, this can also connect to average electricity usage.

A sensible approach is:

1. estimate your combined standby load;
2. check the easiest devices first;
3. switch off what does not need to stay on;
4. avoid switching off essential equipment;
5. use your own unit rate for final calculations.

For a more accurate estimate, use your actual tariff and measured appliance wattage.