How Many Watts of Electricity does a Iphone Charger use?

Real power-use measurements from a iphone charger.

How Much Power does a Iphone Charger use

Iphone Charger: 4 Watts


  • The iphone has a small rechargable battery. On my phone, with my usage, a charge lasts about one day. It doesn't take very much energy to charge the phone, but it does take about an hour.
  • There is some concern that if you leave your transformer cord plugged into the wall that it uses some electricity. It doesn't.

Power Use

  • Watts: 4
  • Kilowatts: 0.004 Kw.

Operation Cost

  • cost per minute: 0 hundredths of one cent (0 ¢)
  • cost per hour: 5 hundredths of one cent (0¢)
  • cost per day: 0¢
  • cost per month: 7¢

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Power use of these items was actually tested. Individual items will vary, but these are the actual measurements.