Maybe you’ve just started to look for a house, or you’ve found a property that you love and are curious about what it’s worth. Or perhaps you’re thinking about listing your current home for sale. Because home values are constantly changing, how do you know what your property is really worth? Are property value lookup tools even accurate?

Both buyers and sellers have good reason to get an objective view of a home’s value before signing on the dotted line.

Richard Stives is an experienced, top-selling Realtor in El Paso, Texas. According to him, sellers want to know a property’s value so that they can be sure they’re not leaving money on the table, whereas buyers want to know they’re paying a fair price and that the home will appraise.

If the home appraisal comes in lower than the offer, which happens only about 8% of the time, buyers “have to bring money to the table to bridge an appraisal shortfall,” explains Stives.

Here’s what to know and where to look to help ensure you make a sound real estate investment or get the best price when you sell your home.