The term 'Carpet Cutter's Calculation' refers to the job of a carpet cutter, which is a person who measures and cuts carpets for installation. The crossword solutions for this term are AREA, which is a four-letter word. AREA is a mathematical term that is used to measure the size of a two-dimensional surface, such as a carpet. Carpet cutters use this calculation to determine the amount of carpet needed for a particular space.