average price per square foot installed granite countertops
1 No-stain slab granite countertops cost $50-$90 per square foot, or $1,500-$2,700 for an average kitchen, typically including professional installation. Granite-cutting circular saw blades cost about $20; granite-cutting drill bits cost about $10. 2  Most granite countertops require frequent resealing treatments to avoid damage to the surface. 3  Sealant costs $15-$20 per ounce; one ounce treats 50 square feet of countertop.