not counting that 40hrs weeks accounts just for working hours. You should add 1hr per day for lunch or equivalent pause, and often 2hrs\day for commute. You easily end up to 55 hrs that is ~50% of your waking time. You should add all is needed to sustain a full time job that requires you to be conscious of what you're doing, so I'd add some routine habits that make this possible, like maybe time to readapt your consciousness from work environment where you just lived and focused thoughts the last 9 hours, as I feel to need. You sell your life when working full time for someone's(something...maybe) else enrichment. Those 40 hours a one give to someone else are the most profitable hours a one have