All of the ropes at Knot & Rope Supply are measured by their diameter. It can be easy to confuse the diameter of the rope with the circumference. Just remember, diameter is measured from one side to the other, NOT around the rope.
Knot & Rope offers a large variety of diameters of rope. Based on your search, you are probably looking for a 1 inch or larger. Below are some various 1", 1 1/2", 2" and even 2 1/2" ropes for you to choose from.