What Amps Measure...
Your vacuum cleaner, or most of the ones you may want to purchase, will be 12 amp vacuum cleaners. Amps measure the power of the electrical current going from your outlet to the motor of your vacuum cleaner. While most vacuum cleaners have "12 Amps" prominently displayed on their advertising material, having a 12 amp vacuum cleaner doesn't mean you have the most powerful cleaner on the market. It's up to the manufacturer to design a motor that uses the amps productively. Some 12 amp vacuum cleaners clean better than other 12 amp vacuum cleaners. There are several other factors that influence cleaning power of a vacuum cleaner.
Factors That Influence Cleaning Power...
Design of the motor.
Way the system filters dirt.
Height adjustment on the carpet/surface.
How you maintain your vacuum cleaner.