Meandering amount detection method and meandering control method for metal strip

A meandering amount detection method for detecting a meandering amount of a metal strip traveling in a state of being overlapped in a plurality of stages at intervals, the method comprising:

• calculating an end portion position in a width direction of the metal strip in each of the plurality of stages using
• an angle formed by a reference direction, wherein the reference direction is determined from a reference point, and a direction connecting the reference point and the end portion position in the width direction of the metal strip in each of the plurality of stages,
• a distance between the reference point and the end portion position in the width direction of the metal strip in each of the plurality of stages,
• a distance between a straight line including the width direction of the metal strip and the reference point;
• and
• calculating the meandering amount of the metal strip in each of the plurality of stages based on the calculated end portion position in the width direction of the metal strip in each of the plurality of stages.