In this tough economy we'd all like to earn a little more money. But given the fragile recovery and the throngs of Americans who still remain out of work, now may seem like a bad time to ask for a raise.

Still, many workers are long overdue for a boost in wages. Income growth has been stagnant for much of the last decade even as prices for many goods, such as fuel, education and health care, have continued to rise.

A recent survey suggests that the average worker this year can expect an increase in wages of 3 percent, according to Mercer, a human-resource consultancy. According to data from the Bureau of Labor Statistics, however, consumer prices rose 3 percent in the 12 months ending December, leaving workers to merely tread water when it comes to earning more money.

Workers typically receive raises following annual or semi-annual performance reviews. Those may provide key moments to ask a supervisor for more money, if a meeting is part of the review process, and the increase in pay isn't all you'd hope it would be.

If no meeting is planned, ask to set one up, says workplace-expert Lindsay Olson in a post on U.S. News & World Report. But be sure to be prepared to discuss your contributions to the organization and forthcoming about your pay-raise expectations.

Further, she says, asking for a raise because co-workers make more than you do or the cost of living has risen won't likely seal the deal.

Proving that you deserve more money, Olson says, "needs to be based on your personal performance."

For more about how to ask for a raise, check out this infographic from Mindflash.com, a producer of online training programs.