Cut your coat according to your cloth OR Cut your coat according to your size

The phrase “cut your coat according to your cloth” is preferred over “cut your coat according to your size” because it more accurately conveys the idea of living within one’s means. This suggests that the extent of one’s projects or ambitions should be determined by the resources (cloth) available. 

In tailoring, the amount of cloth available directly limits the size of the garment that can be made. This translates to real-life situations where financial or material resources dictate what can be achieved. 

The idiom “cut your coat according to your cloth” was invented at a time when clothing was often custom-made and tailors would carefully measure and cut fabric to create garments. 

The phrase advises individuals to tailor their ambitions, plans or expenses according to the resources they have. It means being practical and realistic about what you can afford or achieve with the resources you have. In other words, the phrase references the amount of material available for making the coat, which aligns perfectly with the idea of working within one’s means.  

On the other hand, “cut your coat according to your size” while seemingly logical, does not fit as well with the tailoring metaphor, as it would imply the coat’s fit rather than the limitation of resources. This phrase changes the focus from resource management to fit, which does not convey the same message