NEW YORK ( MainStreet) — It's no secret that a bad hire can cast a dark cloud over any company, creating headaches for management and stress for everyone from HR to interns. Unfortunately, the problems don't end there: The monetary cost of a bad hire can exceed 30% of the person's annual salary, according to the U.S. Department of Labor, and 39% of hiring managers surveyed by staffing firm Robert Half said that a poor hire had cost them precious hours of productivity. Even if it's tempting to make a quick decision on hiring, if the person isn't a good fit, it could be a disaster.

"The costs of bad hires include direct expenses associated with recruiting, on-boarding, training and potentially some type of severance package," says Angelo Kinicki, management professor at the W.P. Carey School of Business at Arizona State University.

Although the cost for individual failed hires will vary depending on salary and level of experience, almost one-third of U.S. employers — 27% — said a single bad hire can cost more than $50,000, according to a survey by CareerBuilder.com.

Unfortunately, bad hires are more common than most of us like to think, says Donna Weiss, Managing Director at CEB. Hiring managers surveyed by CEB estimate that 20% of the new hires on their team should never have been brought on. Unfortunately, the attrition of new hires is much higher than that of all employees combined. The average new hire turnover is 23%, compared with 16% for all employees, Weiss says.

"Factoring in that the average cost per hire across all levels is more than $7,000, an organization incurs more than $1.6 million in rework costs per 1,000 hires," she says.

In extreme cases, the cost of a bad hire can exceed 1.5 to two times the employee's annual salary, cautions Russ Hovendick, founder of career consultancy Directional Motivation .

"You've got to find the perfect person to replace the one you're losing," Hovendick says. "Let's say you had a second choice when were hiring — if that person has moved on to another opportunity, then your search will have to start all over again. If you were using an outside agency in your search, then you're going to be looking at a lot of money to advertise the position, recruit for the job and to make another hire."

Don't forget that through all that, you're also paying your full-time employees their hourly salary for the time they spend on finding someone new — and those numbers add up quickly, Hovendick says. Even once you make a hire, more time will be spent on training, introductions and policy and procedures.