how much percentage of your brain do you use?

dear friends
do you think that how much percentage of your brain do you use?
an enduring myth says we use only 10% of our brain, the other 90% standing idly by for spare capacity.
two-thirds of the public and nearly half of the science teachers mistakenly believe the 10% myth.in 1890 William James the father of American psychology said:

scientists could not figure it out for a long time they are crucial to abstract reasoning, planning, and weighing decisions

an adult human brain which accounts for only 2% of the body,s mass consumes 20% of daily glucose burned. this is far more than expected for their relative brain sizes which scale in proportion to body size