When searching how often granite should be sealed, keep in mind that there is a lot of misinformation and little consistency available on the internet. A good rule of thumb is that a standard over the counter penetrating sealer, will last upwards of 10-15 years. The lighter the granite the softer the stone and the darker the granite the denser the stone. So, not all granite colors are equal in durability before they are sealed, so they will vary. Even with that being said, over- sealing your granite countertops will actually dull the polished surface of your natural stone. When too much sealer is used, it cannot be absorbed by the stone, leaving it to sit on top and dry into a blurry residue. This could alarm the owner into thinking they are not properly cleaning granite countertops, which in turn prompts them to use more granite cleaner. If you are using a good granite countertop cleaner on properly sealed stone, you should only need one product to cleanse and condition your natural stone countertops. Save money where you can! Purchase one great natural stone cleaner that addresses all of your marble, granite, quartz, cleaning needs.