Let's take the 1:100 scale as an example. The 1:100 scale means that 1 unit on the model represents 100 units in real life. For example, a room that is 1 inch on a 1:100 scale model would be 100 inches, or 8.3 feet, in real life.

For example, the scale of 1:50 means that 1 mm on the drawing represents 50 mm on the object. This means that the object is 50 times larger than the drawing of it. An object 450 mm long would be represented by a line 9 mm long (450 mm/50).

One-twelfth scale (1:12), sometimes called one inch or one inch to the foot scale is a representation of larger items where one unit of any size is equivalent to 12 inches of the same size (one inch = 12 inches (one foot).

The 1/4 inch = 1 foot scale is the most common in the U.S. and is also referred to as 1/48 size because there are 48 units of 1/4 inch in 12 inches.