How to Build a Dome or Sphere Layer by Layer

A sphere is a stack of circles

A sphere or dome is just a set of circles of different sizes stacked on top of each other. The widest circle sits in the middle of a sphere, or at the bottom of a dome. Each layer above is smaller, until the last one at the top is a handful of blocks.

The generator on this site lists every layer with its own chart and per-row block counts, so you can build one flat layer at a time rather than trying to see the whole curve in your head.

Plan the height before the width

Decide the diameter first, then check that the finished shape fits in the build limits. The wiki’s height limit article lists the Overworld as running from layer −64 to layer 319, and the Nether from 0 up to 255 in Java Edition, so a very tall sphere can run out of room. Bedrock Edition’s limits may differ, so check your own world if you build high.

A dome is half of a sphere, so its height is about half its width. That makes domes much easier to fit than full spheres.

Start from the widest layer

Build the widest layer first. Place its outline or filled circle on a flat, level base, because every layer after it is measured from this one. If the base is wrong, the whole dome will look off, so use the chart and double-check the row counts.

Then move up one block and build the next layer using its own chart. Work upward layer by layer, always finishing one before starting the next.

Use scaffolding and the layer below

A sphere has no flat surface for you to stand on, so build scaffolding to reach each layer. A column up the middle, plus a few spokes out to the edge, lets you walk to every part of a ring. Remove it when you finish.

When the generator shows the ghost of the layer below, use it as a guide. It shows where the previous ring sits so you can see how much each new ring steps in. If your new layer sits on top of the ghost without sticking out, you are on track.

• Build a central pillar first and mark its height in layers.
• Add spokes at the four compass points so you can reach any section.
• Mark finished rows on the chart so you do not repeat or skip any.
• Take scaffolding down from the top once the last layer is in place.

Estimate block totals

Totals grow quickly with size. By the rule used on this site, a solid sphere that is 11 blocks across holds 739 blocks, and one that is 15 across holds 1,791. A hollow shell uses far fewer, because only the surface is placed, but the numbers still add up. Use the generator’s total before you start gathering, and add a margin for mistakes.

Face-sealed hollow shells are designed so that every surface block touches the next by a face. That is what you want for a glass dome, where you need a closed surface.

Finishing touches

Once the shell is complete, add a floor, a door and lighting. Fill in any gaps at corners, then check the dome from inside and outside for stray blocks. Mark the last layers on the chart so you know which parts you have checked.