How much bigger than chairs and how to make a pattern?
Unscrew the chair bottom and turn upside down on top of your fabric. Lift edge of fabric over chair edge and see how much it takes to be able to staple to the bottom. Cut fabric around chair bottom that much. staple middle of front....pull fabric tight and staple middle of back. Do the same thing on the sides and continue stapleing and pulling fabric. Do the same thing for the seat back.
