How much energy does a calculator use? just want to know for a project =)

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A modern hand held calculator with a LCD display uses so little power that I am tempted to call it essentially zero. It can run for months on the smallest battery. Even at only 1 Watt, that small battery would be drained dead in less than one hour, so the calculator must be using much less than 1/1000 of a Watt. 50% 3 Votes

Other Answers (5)

• You should be very suspicious of people who are answering this question in units of watts (or no units at all), as watts are a unit of power, not energy. Power is the time derivative of energy.
  
  You asked, %26quot;how much energy does a calculator use?%26quot; The answer is the power consumption (watts) of the calculator times its duration of use. For example, my scientific calculator is rated at 200 microwatts (0.0002 watts). If I use it for one second, it will consume 200 microjoules (0.0002 joules) of energy. That is a vanishingly small amount of energy. If that energy were obtained via the electric mains rather than from a battery, the calculator could be run for approximately 38 years on US$0.01 worth of electricity. As another illustration, the amount of energy needed to run a 100-watt light bulb for one second would run my calculator for almost 139 hours. 33% 2 Votes
• Mine is solar powered, so I%26#039;m guessing not much. 0% 0 Votes
• The LED calculators use much less than the old ones that used red lights to make the numbers. 0% 0 Votes
• The power is in milli watts, naturally energy requirment will be in milli watt hours 0% 0 Votes
• It depends on the calculator. Check the back of it or in the battery compartment. 17% 1 Vote