Tool · Investor Sam Green

Phantom (Standby) Load Cost Calculator

June 30, 2026 • By the Investor Sam Editorial Team • Reviewed by Berly Sam Varghese, Editor
Phantom load — also called vampire or standby power — is the electricity devices draw around the clock even when switched off or idle: chargers, TVs, cable boxes, game consoles, and smart speakers. Individually tiny, it adds up across a whole home. This calculator estimates the total standby wattage of your idle devices and shows what that constant, invisible draw costs you over a full year.

Example: Number of standby devices: 25 devices · Average standby draw per device: 3 W · Electricity rate: 0.17 $/kWh

Annual phantom-load cost$112
Wasted electricity per year657
Total standby draw75

Worked example

A typical home has about 25 devices idling at an average of 3 watts each, for 75 watts of constant standby draw. Running nonstop that is 657 kWh a year, costing roughly $112 at $0.17 per kWh — money spent on devices doing nothing. Putting clusters of them on switchable power strips and unplugging seldom-used chargers reclaims most of it.

Frequently asked questions

How much of my bill is phantom load?

The Department of Energy estimates standby power accounts for roughly 5 to 10% of residential electricity use in a typical home. The exact share depends on how many always-on electronics you own. This tool lets you plug in your own device count to see your personal number.

Which devices are the worst offenders?

Set-top and cable boxes, game consoles left in instant-on mode, older TVs, desktop computers, and always-listening smart speakers tend to draw the most standby power. Phone chargers left plugged in draw very little each but add up in quantity. A plug-in meter reveals the biggest culprits.

How do I cut phantom load?

Group entertainment and office devices onto switchable or smart power strips and cut them off when not in use, unplug chargers and rarely used gear, and enable true power-off or eco modes instead of standby. These steps recover most of the wasted energy shown here with no loss of convenience.

Is standby power really worth worrying about?

For a single charger, no. But across dozens of devices running every hour of every day, it becomes a steady, year-round line on your bill. Because it costs nothing to switch off idle clusters, phantom load is some of the easiest money you can save.

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Sources

Berly Sam Varghese · Editor, Investor Sam

Berly Sam Varghese is an engineer who treats money the way he treats any hard problem — something to be engineered, not gambled on. He funded years of education and built real financial stability the patient way, by living below his means and investing rather than borrowing. He writes for the person trying to make a greener choice that also makes financial sense. He reviews and approves every article on Investor Sam and checks the figures against primary sources before anything is published. More about our standards.