To measure for a dining room chair cover, determine the following dimensions: 1. Measure the height of the backrest of the seat from bottom to the top of the dining room chair and double it. 2. Measure the overall height of the dining chair, from the floor to the very top. 3. Measure across the centre-front of the seat (outside to outside measurement). 4. Measure across top-back (from outside to outside). 5. Measure the arm length and arm width (inside and outside), if any.