Sphere Calculator is an application that allows you to make a sphere in Minecraft. Please note that Sphere Calculator is not a mod within Minecraft.
Sphere Calculator is a small application that you run to show you where to place blocks to make circles and/or spheres.
Sphere Calculator is written in Java, so if you can play Minecraft, you should be able to run this.
Run Sphere Calculator, then enter a diameter for the sphere you want to build. Hit Draw, and it will show the block placement for the first layer of the sphere.
Click the Next Layer and Previous layers to move between layers as you comte them. You can also enter a layer number and hit draw to jump to that layer.