While the “Zestimate” is pretty common, it’s not often very accurate. It uses approximated values of homes that are similar to yours… but not homes that have been recently sold. It also uses approximations of approximations, which drives it further and further from an actual value reflected by the current market. While no tool can tell you the value of your home as well as the market can, it is always a good plan to get an idea of what it’s worth before selling. This tool has proven pretty accurate (I wouldn’t be paying for it if it wasn’t) and should give you an idea – I can always put a finer point on it (also free to you), at your request.