We all want to make as much money as possible on the job, so if you're not happy with your salary, or can't remember the last time you got a raise, it's time to take steps to change your circumstances. To do so, however, you'll need to figure out why it is you aren't earning as much as you feel you're capable of. Here are just a few possible explanations.

1. You're not boosting your skills

It's easy enough to come to work on time each day, do what's expected of you, and leave once everything is nicely wrapped up. But if you don't make an effort to grow your skills and expand your score of responsibility at the office, your company will probably be hesitant to promote you -- which means you're less likely to get more money anytime soon.

Woman using a calculator

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A better bet? Figure out what you need to do to move up a level at work and invest some of your own time into developing professionally in that regard. Maybe you need certain computer skills, or maybe you need to develop a few key soft skills that many of your colleagues seem to have. You may even need to sit down with your manager and ask directly what it'll take to snag a much-desired salary boost. The key, however, is to be willing to make that effort rather than sit back and let things remain status quo.

2. You don't take initiative

Many of us show up to work, do what we're told, and call it a day. But if you never volunteer for new things or suggest projects that will add value to your company, you're less likely to be rewarded financially. Though putting yourself out there takes guts, the next time an initiative opens up at your company in need of an owner, jump on the opportunity. You may need to work longer hours, at least temporarily, to manage that load, but the payoff could be more than worthwhile.

3. You haven't actually asked for a raise

CareerBuilder reports that 56% of employees have never asked for a raise. But what's interesting is that those who have requested more money have been mostly successful across the board, with 66% of workers getting a pay boost after broaching the topic. If you're wondering why you haven't gotten a bump in salary for quite some time, the answer could boil down to stone cold apprehensiveness on your part to bring the matter to your boss's attention.

So don't let that unhealthy trend continue. Schedule time with your manager to discuss the idea of a raise, and come prepared with compelling reasons why he or she should agree. For example, it always pays to do your research and see what other people with your job title are making. If you can prove that you're earning well below the average, your boss might advocate for a boost. Similarly, go in with a list of ways you've contributed to your company's success. If you can show your manager, with actual numbers, how you've made or saved the business money, that might sway your boss to agree to an increase.

For better or worse, raises aren't a given in today's workforce. Rather, you frequently have to earn that increase. If you work on growing your skills, volunteer to do more, and muster up the courage to ask for an increase, you'll be more likely to wind up satisfied with your earnings.