So, just what size is considered a micro? Generally speaking, a micro is any toy car that is smaller than 1/87 scale, also known as HO scale. I have been asked many times  for the true scale of a micro and that is a really hard question to ask. Like most of the die-cast counterparts, most brands of micros are not made to a true scale - They are made to be a specific length. The height and width are usually different scales then what the length works out to be.

HO used to be the most popular scale of model railroading. N Scale has been gaining popularity since you can have a lot more track in a smaller area. Some model N-Scale model railroad enthusiasts will use Micro Machines, just because there is such a wide variety of models available, and they are really affordable. With this comparison guide you can see the difference in sizes. 

Please note: The cars may be pictured slightly larger than real life.