Abstract: An improvement to a flat bed knitting machine comprises a wheel positioned on the carrier of the flat bed knitting machine. The wheel turns as yarn passes thereover for knitting, thus allowing the wheel to measure the amount of yarn used. A series of magnets positioned on a bar beneath the needle bed send signals to a sensor attached to the carriage of the knitting machine as the sensor passes thereover. These signals instruct a logic circuit contained within a logic circuit control box to accept input from the wheel. The magnets are spaced apart by the distance of a known number of needles. Thus, the amount of yarn used can be divided by a known number of needles to arrive at a stitch size to help in the calibration of the flat bed knitting machine.