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Human Anatomy and Physiology

How much energy does the brain require?


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June 13, 2012 2:28AM

The brain consumes about 25 % of the body's energy when at rest.

So for a typical person, on an average day, this equates roughly to 24 watts (based on 2,500 Calories/day).

But the energy usage of the brain does vary depending on the level of mental exertion. Studies have shown that when performing difficult mental activities, the energy usage of the brain increases.

See the following link for more background: