If you’re interested in buying property, either for personal use or for investment purposes, then you will have to know its market value before you make an offer. Knowing the value of adjoining properties may also offer you some valuable insights on what the property is really worth.

Finding out the value of a particular piece of real estate is now easy with the mushrooming of real estate valuation services sites, many of which offer their services for free. The downside of these sites is that the data they provide will probably not be identical since they use different methods of appraisal. However, by using multiple sites and combining their data with your own observations to come up with a reasonable estimate of the property’s value.

The most well-known of these online real estate valuation services sites is probably Zillow (www.zillow.com), mainly because it received a lot of press coverage when it was launched. Upon entering the address of the property, the site returns a Google map of the target property and surrounding comparable properties which were recently sold.

The site then provides users with a free report, which has a substantial amount of data on the target property, including basic information such as price, lot size and number of bedrooms, as well as data on the comparable properties that you’ve selected. The Zillow report, which is provided for free, also gives an automatic estimate on the property’s value along with a range of values reflecting the data used to make the estimate.

Other sites you can try include RealEstate ABC (www.realestateabc.com) which is also a free site; Domania/Real Estate (www.domania.com or www.realestate.com/avm/) and Ditech (ditech.com/calculators/appraisal/form.do).