Calculating distance between two points with QGIS 2.14.0

I have two shapefiles with the following information:

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  List A: ID 1 | xA | yA | ID 2

  
  


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  List B: ID 1 | xB | yB | ID 2

  
  

{x;y} = {lat;lon}

I want to calculate the distance between two points, e.g. ID 1: distance from {xA,yA} to {xB,yB}.

The KBS is WGS 84 and I need the result in meters. Can anyone tell me how to do that?