Phantom Load: What Standby Power Costs Per Year
October 29, 2026
Many devices draw power even when they are turned off or in standby: televisions, game consoles, chargers, set-top boxes, printers, and smart speakers. This is called phantom load or vampire power. The annual energy for any constant draw is watts × 8,760 hours ÷ 1,000 = kWh a year. Multiply by your electricity price to get the cost.
A device that draws a constant 10 watts uses 10 × 8,760 ÷ 1,000 = 87.6 kWh a year. At $0.16 per kWh, that is $14.02 a year. A household with 40 watts of total standby load uses 350 kWh a year, costing $56.
Skip the math and get your answer instantly:
Open the Unit Converter →Cost by Constant Draw
Use the table to estimate your own situation: measure each device with a plug-in power meter, add them up, and look up the cost. For a different electricity price, scale proportionally: at $0.30 per kWh, double the costs approximately. Typical household standby load is 20 to 60 watts, or 5% to 10% of residential electricity use, according to various studies, though newer devices are better. This is not a fortune, but it is money spent for nothing, and unplugging is free.
| Constant draw | kWh per year | Cost at $0.16/kWh |
|---|---|---|
| 5 W | 43.8 | $7.01 |
| 10 W | 87.6 | $14.02 |
| 20 W | 175.2 | $28.03 |
| 40 W | 350.4 | $56.06 |
| 100 W | 876.0 | $140.16 |
Which Devices Are Worth Attention
Typical standby draws: cable or satellite set-top box 10 to 30 watts (they often never really turn off), game console in instant-on mode 10 to 15 watts, flat-screen TV 0.5 to 3 watts, desktop computer in sleep 2 to 5 watts, phone charger with no phone 0.1 to 0.5 watts, printer 2 to 5 watts, and smart speakers 2 to 4 watts. A set-top box drawing 25 watts costs 25 × 8.76 × $0.16 = $35 a year, worth more than many small chargers combined. Measure rather than guess.
Practical Steps
Use a power strip with a switch for entertainment centers and computer setups, and turn it off when not in use. Use smart plugs with schedules for devices that don't need to be on at night. Change console settings from instant-on to energy saving. Replace very old devices that draw more in standby. Don't expect big savings: if you eliminate 20 watts of waste, that is $28 a year, so spend little effort or money on it. A $15 smart strip that saves $28 a year pays back in about 6 months.
Putting It in Perspective
Compare with major loads: a refrigerator uses 300 to 500 kWh a year, water heating 2,000 to 4,000 kWh, and heating and cooling the largest share. Standby power is a small slice, but one of the easiest to cut. Focus first on big loads, then on the always-on devices over 10 watts. For solar or off-grid homes, standby load matters more because every watt must be generated and stored.
Frequently Asked Questions
How do I calculate yearly cost of standby power?
Watts × 8,760 ÷ 1,000 gives kWh a year; multiply by your rate.
How much does a constant 10 W cost per year?
About $14 at $0.16 per kWh.
Which devices draw the most in standby?
Cable and satellite boxes, game consoles in instant-on mode, and some older electronics.
How can I measure standby power?
With a plug-in power meter.
Is it worth unplugging chargers?
Usually only a little; focus on devices over 10 watts.