168 hours in a week: How can I measure my own economic productivity?

I've been trying to come up with a method to effectively measure my own economic productivity. My idea here is to find a way to figure out if I am optimizing my waking hours to maximize the number of dollars I can make per hour so I can compare different job options. My first attempt looks something like this:

1) Determine the maximum number of available hours.

There are 168 hours in a week. I want to start by determining the absolute minimum hours I need to consume to "get by" on a long term basis. I need to sleep 7 hours a day (49 hours a week). I figure I need another 7 hours a week for food, 10 hours a week for general "getting ready" type stuff such as shopping, showering, laundry, etc. So that leaves a maximum of 102 hours a week that I am available to produce income.

2) Hours consumed by current employment.

I work 8am to 5 pm, 5 days a week. It takes approximately 1 hour for round trip commute time each day. That's a total of 50 hours a week.

3) Hours consumed by other activities.

I'm currently in grad school. This consumes about 12 hours a week for class time, 12 hours a week of outside the class time, and 1.5 of additional driving time. That's 25.5 hours a week.

4) Available hours:

Of my 102 hours a week I am available to produce income, I am currently only utilizing 50/102 = 49%. I am spending another 25% of my time on a non-income producing activity, and the balance of 26.5 hours (25.9%) I am just wasting.

Options to produce more income

There are pretty much two things I can do to make more money: work more hours, or make more money per hour. But how can I effectively compare options? I've looked at other jobs that pay more, but I would also end up working a lot more. The ideal job would be one that pays infinite money with no hours worked. Since I am constrained by reality, the ideal job is one that pays a large amount per hour. And since I have nothing better to do until retirement, the ideal job consumes 100% of my available hours while paying that large amount per hour.

A forumula to adjust income for wasted hours

Let's imagine two scenarios:
A) $2000 week with 102 hours consumed by work = $19.60/hour
B) $1500 week with 50 hours consumed by work = $30/hour

Per hour of work, A is making $19.61 while B is making $30. Yet, that doesn't explain the whole story since B is wasting 52 hours a week of potential income producing time. If B used 100% of the time, they would make $3060 a week.

A) $2000 / 102 = $19.60 x (102/102) = $19.60
B) $1500 / 102 = $30.00 x (50/102) = $14.71

See the difference? B adjusts her income, and ends up realizing that she isn't making as much as she could be.

Let's try another example.
C) $320 week with 40 hours worked = $8/hour
D) $400 week with 20 hours worked = $20/hour

C) $320 / 102 = $3.14 x (40/102) = $1.23/hour
D) $400 / 102 = $3.92 x (20/102) = $0.77/hour

D is obviously making far more money per hour than C, but is WASTING 82 hours a week of potentially productive time. If both C and D worked 102 hours a week, here's how the adjusted formula would come out.

C) 102 hours x $8 = $816 / 102 = $8 x (102/102) = $8
D) 102 hours x $20 = $2040 / 102 = $20 x (102/102) = $20

The point I am trying to make here is that a job that pays more per hour is only better when you can also work the same OR more hours. The ideal is using ALL of your productive time producing income, and not ending up wasting any of it.

The part time job example

E) $1000/week with 50 hours consumed = $20/hour
Adj E) $1000 / 102 = $9.80 x (50/102) = $4.80/hour

Add McDonalds job, 20 hours paid per week @ $6 an hour, 4 additional hours consumed from commuting/etc. $120/week for 24 hours.

E) $1120/week with 74 hours consumed = $15.14
Adj E) $1120 / 102 = $10.98 x (74/102) = $7.97/hour


The purpose of this formula is to quantify, in purely monetary terms, the income produced from time spent working AND the value of not wasting extra hours. So many people want to retire early, but instead of spending more time producing additional income - they spend time playing with their investments. Others are satisfied with their yearly salary, but never pause to consider the number of hours they need to work to produce this salary and other available options.

I'd appreciate it if you'd leave comments and suggestions to improve this formula.