it depends on the chair
you will need about 6 yrds
1 yard = 3 feet.
There are 3 feet in a yard & 12 inches in a foot. Do the math.
A normal yard is 36 inches. However, a traditional clothyard is 39 inches (extra makes up for the seams) so it would depend on which one is applied in the store or area you buy from/in.
How to Repair a Dining Room Chair - Part 2
How to Repair a Dining Room Chair - Part 3
How to Repair a Dining Room Chair - Part 4
How to Repair a Dining Room Chair - Part 5