Where a the hem of your pants should sit.

I often see and wonder whether men know how to dress accordingly, espacially when it comes to the lengths of pants/ trousers.
Let me start off by saying that it depends on whether it is casual, formal or high fashion items.
The width of the bottom lenght of the pants/trouser is also very important.

Take for instance a wide trouser leg ( like in the 70's), that sits as high as your ankle. That will just look ridiculous, unless it's high fashion with a statement....and the right shoes/boots!

So, the wider the bottom of your pants, the longer you wear it, never allowing the hem to sweep the floor!

The narrower the bottom of your pants, the higher you can go. No rule in how high, but depending on the style and/or if it's a high fashion item.

The rule for formal trousers:
This applies to straight legs in trousers.
The hem should be about 1 - 2cm above the heel of your shoes.
The front of the leg will make a small break, which means it will have a slight fold.
The modern formal trouser ( like in the 60's), has got a tighter leg and  tapered at the bottom, which means that the hem will sit higher at the back of the heel of your shoes.
The break in front of your trouser will be more, but that is how it should sit.  There should be one or two folds, but that's it! The right shoe should be worn with these pants.

More casual or fashionable pants can have slightly more folds.......