This mainly depends on the length and shape of your dining table. On average, you need 55–60 cm of table space per chair. Always first check the width of your dining chair and the shape of your dining table before following the guidelines below.
Guidelines:
140 cm → 4 chairs
160 cm → 4 to 6 chairs
180 cm → 6 chairs
200 cm → 6 to 8 chairs
240 cm → 8 chairs
Extra tip: with slender chairs or without armrests, it is often easier to fit extra seats.