There are plenty of negotiation tactics out there that will help you fight for the salary you deserve, but you can't really start that battle without first knowing just how much that deserved salary is. The recruitment website Glassdoor just created a tool that will arm you with the knowledge you need regarding your market value; it's aptly named Know Your Worth , and you can use it for free through Glassdoor's website.Know Your Worth calculates your earning potential based on information you input. All you have to do is answer a few simple questions about your current base salary, years of experience, location, and education level. The tool then compares how much you earn to salary and job market data, and, within seconds, you receive a personal and private evaluation.From there, you'll learn how much you should be making, if you're currently being paid fairly, and if you have the potential to get a salary increase. Along with your results, Know Your Worth also shows you relevant listed jobs in which you could earn more, and it allows you to explore other careers and their salaries. We all want to be in control of our careers, and Know Your Worth puts you one step closer to achieving just that.