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One of the most painful realizations I had when I started getting my financial life in order was that I wasn't earning as much money from my job as it seemed.

My salary at the time of this realization was about $40,000 a year, so let's use that as a baseline.

Now, on the surface, that's really good money. If I worked 40 hours a week for 50 weeks a year, I would be earning $20 an hour, right?

Well, that's not entirely true.

First of all, we have taxes. Federal income taxes, state income taxes and FICA taxes. Federal taxes would eat about 11% of my paycheck, state taxes would eat about 4% or so, and FICA would eat about 2%.

Second, I had to pay for my commute. This was about 10 miles each way, and it was the primary reason I owned a vehicle. So, let's tack on top of that a monthly car payment of about $200, about $40 a month in gas, about $30 a month (prorated) in maintenance expenses, and about $40 a month in insurance, just to keep that car on the road.

I also had to wear a nicer wardrobe. I spent $200 a year to make sure I dressed appropriately for meetings, conferences, and the like -- and that's a low-end estimation.

I also ate at least two meals eaten out a week, costing $10 each. There was travel about three times a year, when many of my expenses would be challenged, meaning each of those trips set me back about $100 out of pocket.

Not only that, there were many times where I would put in extra, unbilled hours to meet a deadline. I easily averaged 50 hours a week at work.

Plus, there was the time I spent traveling -- about 50 hours spent going to places I didn't want to be per trip. And there was the time spent commuting -- about 40 minutes per day. There were also work-related meals and other activities to attend, eating an additional four hours per month.

When you start running the math on this, the equation starts to change.

After receiving my $40,000 salary, I'd pay out $6,400 in taxes each year. I'd pay out $3,720 in commuting costs. I'd pay out $200 in wardrobe costs. I'd pay out $1,000 in extra meals each year. I'd pay out $300 in extra travel expenses.

Suddenly, my $40,000 salary became $28,380.

Now, I'd work 40 hours a week, totaling 2,000 hours per year, right? On top of that, I'd add 10 hours of unbilled work a week (over 50 weeks), three hours of commuting a week (over 50 weeks), 150 extra travel hours a year, and 48 extra hours of activities a year. This would bring my total up to 2,848 hours, or an average of 57 hours a week spent devoted to my job.

My job is suddenly paying me less than $10 an hour.

Of course, there were other job benefits that had some significant value, but frankly, I wasn't actually using them. My wife and I sat down and compared the health insurance offerings at our two jobs, and her insurance was far better than mine, so we used her insurance. I had no use for my employer's life insurance option, either, and its retirement plan wasn't particularly strong. These things do have value when you're comparing jobs in this way, but only if you're using them.

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Amazingly, I was actually earning more money that I could keep with my part-time job as an undergraduate. I earned $12 an hour. There were no travel costs, no wardrobe costs, no extra activities, no unpaid hours of work (I kept a diligent time sheet), no commuting expenses (I worked really close to where I lived). I would be left with more than $10 per hour working at this job.

On a per-hour basis, my part-time job in college was more lucrative than my first "good" job after college. It was also less stressful and far less intrusive on my time.

One of my closest friends at the time made $7.50 an hour working at the night shift at a local gas station right after college. The gas station was just down the block from his apartment, and he'd spend most of his time there reading or practicing his sketching, as he'd have a customer maybe once every 15 minutes. He didn't have a car, and on the rare occasions when he needed to go somewhere, he would take the bus.

It often seemed that he had more money to spare than I did. At the time, I thought it was just an illusion, but when you start running the numbers this way, it's not entirely surprising, particularly if he was paying lower rent and lower utilities than I was.

Realizations like this one are what persuaded me to make a scary career leap and start working on my writing full time. Doing that meant that I no longer had a commute (saving on car maintenance, fuel and time) or any wardrobe costs or eating-out costs. My time spent on work was actually spent on work. There was no more travel -- I've only been tempted to travel related to ny new work once, and that one time was canceled due to a family illness.

On the surface, my salary dropped through the floor when I made this move, but when I started running the numbers like this, I began to realize that my hourly income really wasn't going down much.

Whenever you're thinking about your next job or your next career move, you need to think through these kinds of things. Often, a job that looks like it earns you great pay or is a great opportunity really isn't either, and a job that seems like you won't be earning much can actually leave you with a lot of money in your pocket. When you take into account things like stress and schedule flexibility, sometimes the "low-end" job is just the job for you, particularly if you're simply working to earn a paycheck and are focusing your energies on getting a side business or other opportunity off the ground.

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