Entertainment center
Measure the TV, receiver, console, streaming box, soundbar, subwoofer, and powered antenna separately or as one switched group.
Electronics
Standby Power Cost Guide
Standby power is the electricity a device uses while it is not performing its main job but remains ready, connected, displaying information, or communicating.
How to calculate standby cost
Standby wattage is usually small, but idle hours can be long. Estimate the hours per day that the device is in that state, then use the standard watts-to-kWh formula. Calculate active use separately so the two states are not counted at the same time.
Standby cost = Standby watts / 1000 x Standby hours x Electricity rateAt $0.18 per kWh, a continuous 5W standby load costs about $0.65 per month or $7.88 per year.
How much electricity does standby power use?
A continuous 1W standby load uses 0.72 kWh in a 30-day month and 8.76 kWh in a year. At $0.18 per kWh, that is about $0.13 per month or $1.58 per year. A measured 10W group uses ten times as much: 87.6 kWh and about $15.77 per year at the same rate.
Example standby costs at $0.18 per kWh
| Continuous standby load | Monthly energy | Monthly cost | Yearly cost |
|---|---|---|---|
| 1W | 0.72 kWh | $0.13 | $1.58 |
| 5W | 3.60 kWh | $0.65 | $7.88 |
| 10W | 7.20 kWh | $1.30 | $15.77 |
| 25W | 18.00 kWh | $3.24 | $39.42 |
These examples assume the listed load continues for 24 hours every day. Subtract active-use hours when a device has already been counted in another operating state.
Off, standby, idle, and sleep are different states
A television waiting for a remote command is in standby. A computer that is awake but doing little is idle and usually draws more. Sleep mode saves system state while reducing power, but network wake features and connected accessories can remain active. A charger with no device attached may have a very small no-load draw, while a dock powering peripherals can use more.
Label each measured state instead of describing everything as "off." This makes the result repeatable and shows whether changing a setting is more useful than disconnecting the device.
Standby power consumption examples
Search results often group standby power, vampire energy, idle watts, and sleep mode together, but the cost depends on the actual measured state. A 2W standby device left ready all day uses about 1.44 kWh per month, while a 10W idle device uses about 7.2 kWh per month.
When several devices share a power strip, add their standby watts before calculating cost. For example, a TV, streaming box, game console, and soundbar can cost more together than any one device suggests by itself.
Where to look first
Prioritize groups of equipment and devices with network, display, or quick-start features.
Computer workspace
Include monitors, docks, speakers, printers, external drives, and network equipment. Confirm that sleep settings actually activate.
Kitchen controls
Microwaves, coffee makers, and ranges may power clocks or network features. Their standby draw is separate from short high-power heating periods.
Always-needed equipment
Routers, security systems, medical equipment, refrigerators, and essential controls should not be disconnected merely to remove standby consumption.
How to measure a low standby load
Use an energy meter that can resolve low wattage. Let the device finish updates, charging, or cool-down before recording its settled state. If an instant reading fluctuates or rounds to zero, accumulate energy for a day or longer and divide by elapsed hours to find average watts.
Average standby watts = Measured kWh x 1000 / Hours measuredFor a collection of devices on one power strip, first measure the whole strip, then disconnect one device at a time if you need to identify the largest contributor.
When switching power off makes sense
A switched power strip can help when several nonessential devices share the same usage schedule. Smart plugs can automate a schedule, but the plug also consumes power, so compare its own draw with the load it controls. Built-in sleep, eco, auto-off, and quick-start settings are often simpler and preserve normal operation.
Avoid cutting power to equipment that requires continuous operation, safe shutdown, remote access, scheduled updates, temperature control, or medical reliability. Check manufacturer instructions before switching a load.
Standby power FAQ
How much electricity does standby power use?
A continuous 1W standby load uses 8.76 kWh per year. At $0.18 per kWh, that costs about $1.58 per year. Multiply those figures by the measured standby watts.
How much does standby power cost per month?
At $0.18 per kWh, a continuous 5W standby load costs about $0.65 per month. Double the watts or hours and the cost doubles as well.
What is vampire energy?
Vampire energy is electricity used by devices that appear off or idle but remain ready, connected, charging, displaying a clock, or listening for a remote command.
Do phone chargers use electricity when no phone is connected?
Many have a small no-load draw, but the amount varies and can be difficult to resolve on a basic meter. Measure the charger or use reliable model information before estimating savings.
Is sleep mode the same as turning a computer off?
No. Sleep normally uses much less than an awake computer but may still power memory, wake features, docks, or accessories. Shutdown can also retain a small standby load.
Should I unplug every device?
No. Start with measured, nonessential loads that stay idle for long periods. Safety, convenience, equipment requirements, and the energy used by switching devices should be considered.
Sources
Research and government guidance for standby and appliance energy measurement.
- Standby PowerLawrence Berkeley National Laboratory
- Estimating Appliance and Home Electronic Energy UseU.S. Department of Energy
Compare active electronics use
Estimate active cost first, then add measured standby as a separate operating state.
ElectronicsGaming PC Cost CalculatorCompare active use before adding standby separately.ElectronicsTV Cost CalculatorCompare active use before adding standby separately.ElectronicsLaptop Cost CalculatorCompare active use before adding standby separately.ElectronicsDesktop Computer Cost CalculatorCompare active use before adding standby separately.
Related electricity guides
Measure low loads, use the cost formula, and choose practical savings actions.
MeasurementHow to Measure Appliance Electricity Use AccuratelyMeasure appliance electricity use with label watts, a plug-in meter, annual kWh, or circuit data.BasicsHow to Calculate Electricity CostUse watts, hours, and price per kWh to estimate running cost, including cost per hour by wattage.Saving EnergyAppliance Energy Saving TipsPractical ways to lower appliance running costs at home.