Many people have dining room chairs that have seats that “pop-out” (unscrew from the chair frame). These chair seats can be easily recovered with new fabric. As a general rule, using 54″ wide fabric, 3/4 yard will work for 2 chairs. Three-quarters yards will give you two pieces that are 27″ x 27″. If you have four chairs, you will need 1.5 yards, six chairs takes 2.25 yards, eight chair seats take 3 yards, and so on.
If your chair seats have cording, allow 7/8 yard for two chairs.
If you chair seats are boxed and corded, allow 1.25 yards for two chairs.