To determine how much equity you have in your home, figure out the difference between the appraised value of your home and your current mortgage balance.
Here's a simple formula to calculate your home's equity:
Current Appraised Value of Your Home ($250,000)
minus
Outstanding Balance ($150,000)
=Your Equity ($100,000)
Several websites, such as Zillow or Redfin, can help to provide a rough estimate of your home's value. Looking at what comparable home in your area have sold for is another great point of reference.
Home Equity Calculator