A drawing that shows a real object with accurate sizes reduced or enlarged by a certain amount is called the scale.

The scale is shown as the length in the drawing, then a colon (:), then the matching length on the real thing.

Example: Let the drawing has a scale of 1:10, so anything drawn with the size of 1 would have a size of 10 in the real world,

So a measurement of 150mm on the drawing would be 1500mm on the real thing.