The Energy Consumption of the Human Brain is About 20 Watts
That’s right, the human brain s a hungry little beast. It’s hunger is not only for information, but also for more than its fair share of energy. So how do we know that the human brain consumes about 20 watts of energy?
The average human body uses about 100 watts of energy. We know this by working out the average energy a person consumes in a day, which is 2400 calories. 2400 food calories is 2400 kilocalories. You then have to divide the KCal by 24 hours in a day which leaves you with 100 KCal per hour. The final part of the equation is to convert the KCal to watts, which several online converters will do for us, and gives us an answer of 116.3 Wh. Now remember we said the human brain consumes about 20 percent of the bodies energy? 20 percent of 116.3 Wh is 23.26 Watts, which is close enough to 20 watts for us.
Now for something totally amazing. Scientists believe that to replicate the human brain they will need a processor that is at least 10 Megawatts to operate. That’s about the same size as a hydroelectric plant.
So if you ever feel as though you aren’t that bright, just remember that your brain, no matter how smart you are, could potentially be as bright as a 20 watt light globe. Because that’s how much energy the brain consumes, even if you don’t realize it.