<p>As others have said hours worked per week varies quite a bit from person to person and company to company. I’ve worked in environments where it is rare for any salaried employees to work significantly more than 40 hours per week, even when behind on important deadlines. And I’ve also worked in environments where it is common to work far more than 40 hours (common, not mandatory).</p>
<p>One advantage to being a salaried engineer is they often have flexible hours. At the company where I currently work, we do not need to arrive and leave at a specific time or even list number of hours worked per day/week on a timecard. I like to sleep in later than most, so I typically arrive to work near 10AM. I sometimes take a multi-hour lunch break, giving me time to take my dog to the dog park or attend various appointments. One of the engineers I work with keeps more varied hours than I do and arrives to work after lunch some days and before I come in on others. If an engineer needs to leave early one day or needs to leave the office miday for a couple hours, it’s not a big deal. A few work from home from time to time instead of coming in at all. The main criteria is attending all relevant meetings and usually being around during the core hours, particularly for those working on projects that require a lot of interaction with other engineers. I’m sure many other companies and types of engineers have completely different situations. </p>