I am pretty sure mine is off; it is showing plus or minus 3-4 degrees on a lot of floors and tables in my house. Our house is not level but it should probably be less than 1 degree based on some measurements that the foundation company recently took. Also, it is quite different than the results I am getting with the cheap torpedo level I have. Does it matter for me, probably not. I don't have any racecars to crash. It would be nice if it could be fixed with software though I don't know if that is possible.