Tile is extremely durable and is ideal for long-lasting and durable floors. The PEI Scale was established by the Porcelain Enamel Institute to help create standards consumers could rely on to help determine which tiles to buy for which purpose. The PEI Rating is an indication of tile hardness, and PEI floor ratings are valuable to guide tile choices for different projects. Ceramic and porcelain tiles are rated, though most people seem to be more concerned about the PEI Rating of ceramic tile. Use the right tile for the right surface and you'll be a happy consumer.