Did You Know? May 12, 2011 20% : 400-500 (BBC Focus) Your brain, in general, accounts for about 20 per cent of your total energy requirements. That's an average of 400-500 calories a day, but it varies according to how hard your brain is working. Share on: Facebook Twitter Pinterest Google + Previous articleLook at This Chart Next articleYoung Music… You may also like October 30, 2019 70% July 31, 2019 35,000 Be first to comment Click here to cancel reply. Cancel replyComment Name * Email * Website Save my name, email, and website in this browser for the next time I comment.