The inside diameter is just under 3 inches.  Stackable, classy, sparkly. Rimmed rather than flat for added protection.   The last picture shows ribs to elevate glass slightly to stay out of moisture.

Add a touch of retro style to your beverage service with this single vintage coaster. The clear, cupped design features a sunburst pattern that will complement any decor. The coaster has a diameter of 3 5/16" and is perfect for protecting your surfaces from water rings and spills.

The coaster is a great addition to any home bar or entertaining space. The single coaster is perfect for those who love to host guests. Whether you're serving up cocktails or just enjoying a cold beverage, the coaster will keep your surfaces looking great.