My dad instilled in me the notion that to be successful at work you need to be the first one into the office and the last one out at night. And while I found it considerably easier to follow that advice before I had a kid, his general intuition holds -- working more hours leads to success in the form of higher earnings. I know my dad truly meant to convey the compounding power of hard work over the course of your career, but I'm going to take him literally and calculate the optimal number of hours to work with the goal of maximizing earnings. Put differently, at what point does an extra hour of work stop increasing your earnings and instead just provide fodder for "busy boasting" or "humblebragging"? According to the most recent Census data, your earnings rapidly rise as a function of your hours worked... up to the 55 hours per week mark. After that point, earnings don't really increase for the average earner -- no matter how many more hours they work per week. Let's take a more detailed look at exactly how increasing your hours worked per week increases your earning potential. Or jump to a summary of practical tips I learned from the analysis.

Earnings By Hours Worked

I started by finding how much an average worker earns based on their reported weekly hours worked.



This graph is pretty busy, so let's break it down a bit. Earnings Around 5 Hour Increments

There's a quirk in the data around round numbers -- spikes occur in increments of 5. My take is that salaried workers round to the nearest five while hourly workers provide specific hours. On average, salaried workers make more than hourly workers, hence the spike at round increments.



So let's focus on what I call the 5's. Diminishing Margin Returns To Hours Worked

Ok, there we go. Now the graph is managable.



If you've ever wanted to see a textbook graph of diminishing marginal returns, this would be it.



There's an obvious trend of increased earnings the more hours you work per week, but that falls off the more you work.



Quick note: the data on people working more than 80 hours isn't robust, so I'm going to remove it going forward. Three Types Of Returns

There are three clear parts to this graph:

1. Non-Linear Returns: 35 to 45 hours

2. Linear Returns: 45 to 55 hours

3. No Return: 60+



Most people are like me -- after about 55 hours of work in a week, you're just working to work. Most everyone who works more than 55 hours does not see an earnings increase. Non-Linear Jumps In Earnings

The most efficient return for working more hours occurs when going from 40 to 45 hours, a 12.5% increase in hours worked nets a 42.3% increase in earnings.



The second most efficient jump occurs from 35 to 40 hours -- a 14.2% increase in hours worked for a 41.7% increase in earnings. Mostly Linear Improvements

Increasing your hours worked from 45 to 55 comes out to a 31% increase in earnings for a 22% increase in earnings. This section of the improvement is essentially linear and what I would call "worth it".



Why is it "worth it"? Because the absolute bump in salary comes out to about $23,000/year or about $44/hr. I'm willing to put in the hours for that benefit. Welcome To Busy Boasters' Plateau

If we can equate earnings to productivity, working more than 55 hours a week is where productivity goes to die.



You should probably re-consider your life choices if you're in this group of people, unless of course you're my wife. In her case, putting in the 80hrs a week for residency and fellowship will pay off. More on that later.

Which Professions Let You Take Advantage Of This Trend? From the data above, if you want to maximize your earnings, it pretty clearly shows that you should try to work about fifty five hours a week. However, you also want to be in a profession that allows you to earn non-linear returns on your time spent working. Which brings me back to my wife. She's put it in insane hours the past 10 years in medical school, residency, and fellowship at below average pay, so that she can become an attending physician. When you think about it, the change in pay equates to essentially changing careers from a staff employee to manager. Not surprisingly, doctors are the second most efficient profession for turning long hours worked into earnings -- 54 hours a week with annual earnings of $237,000. That's an effective $84/hr. On the other side of the spectrum, "Graders And Sorters of Agricultural Products" are the least efficient profession working 42.4 hours a week for $19,320/yr.

Which Professions Most Efficiently Turn Hours Into Earnings? Below, I plot the relationship between hours worked and earnings while trying to highlight the most efficient earners -- those with the highest hourly rate.