The cost of a marble slab can vary significantly, typically ranging from $50 to $200 per square foot[1]. On average, expect to pay around $60 to $75 per square foot for marble countertops[1]. The overall cost to install marble countertops ranges from $40 to $150 per square foot, encompassing materials, fabrication, installation labor, and supplies[3]. For an average-sized kitchen, the total installed cost ranges from $1,200 to $6,000[3].