WattMath

Vampire Load Auditor

Estimate the annual energy cost and waste from electronics and appliances that draw phantom power when switched off or in standby mode.

Your Devices

Device Name
Standby W
Qty
W
×
W
×
W
×
W
×
W
×
W
×

Use a Kill A Watt meter to measure standby power, or see common values below

Common standby power reference
TV (LED)5W
TV (Plasma)15W
Gaming Console10W
Cable/Satellite Box20W
DVR25W
Computer5W
Computer Monitor3W
Laptop Charger4W
Phone Charger2W
Tablet Charger2W
Microwave3W
Coffee Maker2W
Printer5W
Sound Bar8W
Smart Speaker3W
Router/Modem10W

Standby Power

Vampire load (phantom power) is electricity consumed by devices when they're switched off or in standby mode. It can account for 5-10% of your electricity bill.

  • Cable boxes: 15-30W even when "off"
  • Gaming consoles: 5-15W in standby
  • Phone chargers: 1-5W when plugged in
  • Smart speakers: 2-4W always on

How to Use

  1. Add devices with their standby wattage
  2. Enter your electricity rate from your bill
  3. Click Calculate to see annual waste and cost

FAQ

What devices have the worst vampire load?

Cable/satellite boxes and DVRs are often the biggest offenders at 20-30W. Gaming consoles, older TVs, and devices with external power adapters also tend to draw significant standby power.

How can I measure standby power?

Use a plug-in power meter (like Kill A Watt) to measure the wattage when a device is off or in standby. Measure for at least 24 hours to get accurate readings as some devices cycle on and off.

Are smart power strips worth it?

Yes, smart power strips can cut power to peripherals when the main device is off. For an entertainment center with $50-100/year in vampire load, a $25 smart strip pays for itself quickly.