Quite often gauss magnetic strength is misquoted or exaggerated. One common misunderstanding is the difference between what is called the Manufacturers Rating and the actual Surface Gauss Rating of a magnet, as one figure is much higher than the other, and represents two different ways of measuring the strength.
Manufacturers Rating: Technically this is called the Magnetic Remanence (Br) of the magnetic material and is a property of the magnet when measured in the manufactures original magnetizing equipment, in what's called a closed circuit. It indicates the magnetic field strength remaining inside the magnet (or at its core) and represents a grade of magnetic material. This measurement is much higher than the surface gauss reading.
Surface Rating: The gauss rating is measured on the surface of the magnet and represents the magnetic flux density generated outside the magnet body. Strictly speaking this is the rating which is most useful to end users as this indicates the accessible gauss of the magnet.
Surface Gauss alone does not tell you the strength of a magnet. If you have two different sized magnets with the same Surface Gauss - the larger magnet will be stronger. Or, you could have a small magnet with a high Surface
Gauss that will pull less than a larger magnet with a lower Surface Gauss.