In order to know how to pick a chair, it is fair to say that chair dimensions can vary drastically from design to design, especially considering the vast style options available. For instance the seat height on a bar stool can vary greatly from a standard kitchen chair.
For the most part though, it is fair to assume the following typical chair dimensions. Seat width: 16″-20″ Seat depth: 15″-18″ Seat height from floor: 18″-20″ Armrest height (full): 8” Armrest width: 2″ Average Set back of armrest from front: 2″-3″ Seat back height: 16″-20″ Specifications for Different Types of Seats (Listed dimensions are based on average-sized adults).
Dining Chair: The seat height averages 18″ to 20″, seat width averages about 15-1/2″ in back and 18″ in front, and average seat depth is 16″ to 18″. If armrests are used, they should be 7″ to 9″ above the seat but able to fit under the table apron. The average width between armrests at the front of the chair is approximately 19″.
Desk Chair: Most specifications for a dining chair apply here. Occasional Chair: Should provide a more relaxed, reclining position than a dining chair – seat height is lower (about 16″). Armrests are recommended for easy in/out and they average 5″ to 8″ in height and 2″ to 4″ in width. Sofa/Loveseat: The seat height ranges from 16″ to 18”. The seat back typically rises 15″ to 18″ above the seat. Armrests generally protrude 4″ to 8″ above seat. The overall width of a loveseat is about 56″ to 60″ – 24″ per person, plus 4″ to 6″ for each armrest. A full-size sofa measures about 90″ in overall width.
Bar Stool: In general, the seat of a bar stool should be 10″ to 15″ below the top surface of the bar. For a normal bar that is 42″ high, a seat height of 30″ to 32″is standard. The seat back is typically 10″ to 14″ above the seat. The seat width ranges from 15″ to 18″ and the seat depth ranges from 12″ to 16″ (16″ to 17″ diameter if the seat is round). A stretcher 18″ below the seat provides a comfortable resting spot for the occupant’s feet.
Counter Stool: Most specifications for a bar stool apply here, except that for a standard breakfast island/counter that is 36” high, a seat height of 24” to 26” is standard.