There are two methods many people use to determine their homes value, an appraisal and comparative market analysis.
Appraisals vary in cost and are defendable in court. They average about $300 for a single family home and more on multi-family dwellings. Appraisers review numerous factors and base information on recent sales of similar properties, their location, square footage, construction quality, excess land, views, water frontage and amenities such as garages, number of baths, etc.
A comparative market analysis on the other hand is an informal estimate of market value performed by a real estate REALTOR® or broker. It is based on sales and listings that will compete with your property that are similar in size, style and location. A range of values will be determined thus arriving at a probable market value. Many REALTORS® offer a free analysis anticipating they will have a new client.
The analysis or opinion should be in writing and should involve professionally accepted appraisal practices.
Some individuals do their own cost comparison. It may take several hours of research at the county recorders office, where there will be indexes to match street addresses and parcel numbers. Once matches have been chosen a tax card can be used to find the assessed value, size, style, number of rooms, baths, etc.