Gauge refers to the number of surface pile yarns in one inch measured along the width of a tufted carpet. It is determined by the spacing and number of needles per inch on the tufting machine and is expressed as a fraction. A carpet with 1/8 gauge means that there are eight ends of yarn per inch and that it was tufted on a machine with eight needles per inch. In woven carpet, this is referred to as the pitch, which measures the number of yarn ends in 27-inches across the carpet’s width.