As an IT consultant, do you know how much you should be making? This depends, of course, on many variables that are not always easily gauged: experience, skills, industry, education, size and location of company.

PayScale, Inc. has created a business model based on providing potential employees with the data needed to negotiate the best deal. It's kind of a Kelley Blue Book for jobs—not just tech-consulting jobs, but also jobs for health care workers, air traffic controllers, ad executives, even college presidents.

Here's how it works, according to Al Lee, PayScale's top statistician. The potential employee fills out his/her professional information including what they're paid. In turn, they get back a report showing how they match up with others with similar profiles. Lee says the anonymity afforded by the PayScale Web site encourages honesty. "Why lie or exaggerate if you're not really trying to impress anyone?" Lee asks. He says PayScale, based in Seattle, also gets better information than other sites because it goes directly to the source: the employees themselves.

PayScale has profiles of about 4,000 tech consultants in its database. "We focus only on English speaking countries," Lee says. "As a result, we collect information about IT consultants mainly from the U.S. and Canada, but from England and India as well."

Typically, these are down-in-the trenches, get-it-done consultants. In this crowd, project managers and program managers are most in demand. Tech consultants who boast skills/specialties in Oracle, Unix and Java are in high demand as well. Consultants who focus on SQL Server and Microsoft office command significantly less (see chart, below).

The more experience, the fatter the paycheck. IT consultants with 20 years or more typically are paid median salaries of just under $100,000, Lee says, whereas beginners with less than a year on the job draw $52,000. California and New York offer the highest salaries—$79,000 and $77,000 respectfully. Despite a shaky economy, salaries seem to be holding firm in those states and nationally, Lee says.

In other regions such as India, the salaries of IT consultants are on the rise. "A mid-career tech consultant in India can earn 700,000 to 1 million rupees annually," Lee says. At 40 rupees to the dollar, the high end of that range comes out to only $25,000, not much in the U.S. but excellent pay in Bangalore.

In the so-called by employer category, self-employed tech consultants generate the most income ($77,000). Consultants who work for corporations draw just under $75,000 as do those who work for hospitals. Workers for the federal government can expect about $73,000.

At the low end among employers: schools and school districts ($44,000) and colleges and universities ($50,000). Bonuses for the most seasoned (20-years plus) consultants come in at about $7,300. That's about $1,000 more than those in the 10-to 19-year range get, and nearly four times what newcomers can expect.

As for vacation time, almost no group gets more than two or three weeks. Tech consulting is one profession that doesn't allow much time for building sand castles.