Sphere generator for Minecraft

How to use it

1. Enter the diameter in blocks, or switch to Ellipsoid for a width, height and depth of your own.
2. Choose solid, hollow or hollow with a thick shell.
3. Use the slider or the layer buttons to move through the layers. The faint outlines show the layer below.
4. Download the current layer, or the sheet with all layers, and build from the bottom up.

How the sphere is calculated

The generator slices an ideal sphere into horizontal layers. A block is placed when the centre of its cube lies inside the sphere. With a diameter d, the block at column i, layer j and row k has its centre at (i + 0.5 - d/2, j + 0.5 - d/2, k + 0.5 - d/2), and it is part of the sphere when x² + y² + z² ≤ (d/2)². Every layer is therefore a filled circle, and the circles get smaller as you move away from the equator.

For the hollow versions the tool removes the inside. A block stays when at least one of its six face neighbours is empty (hollow), or when any of its 26 neighbours including edges and corners is empty (hollow, thick). The thin shell is one block thick across every face, and the thick shell never leaves a diagonal gap.

A worked example: a 21 block sphere

A sphere with a diameter of 21 has 21 layers. The bottom layer is a flat disc of 37 blocks, the equator layer is a disc 21 blocks wide with 349 blocks, and the layers between climb in steps: 37, 97, 145, 193, 241, 277, 293, 325, 341, 349 and then back down. Solid, the whole sphere is 4,945 blocks, which is 77 stacks and 17 blocks. Hollow with a thin shell it is 1,082 blocks, 16 stacks and 58 blocks. Thick hollow is 1,850.

The ideal volume of a sphere with this diameter is about 4,849 cubic blocks. The block version holds slightly more because squares near the surface are counted whole when their centre is inside. The difference is small and stays under three per cent for sizes you would actually build.

Block counts for common sizes

The hollow count grows roughly with the square of the diameter and the solid count with the cube. That is why a hollow sphere is almost always the right choice. A solid sphere of 51 blocks would need over a thousand stacks, a hollow one about 104.

Sphere size guides

Every size below has its own page with the layer by layer counts.

• 7 blocks
• 9 blocks
• 11 blocks
• 15 blocks
• 21 blocks
• 31 blocks
• 41 blocks
• 51 blocks
• 64 blocks

How to build a sphere without losing your place

Build from the bottom layer up and finish each layer before you start the next. Use the faint outline of the layer below as a guide: every block of the new layer should sit on or next to a block of the old one. For a big sphere, put a tall pillar in the centre and mark the layers on it with a sign or a different block. You then always know which layer you are on and where the centre is.

Work from the middle outward when you have to place blocks in the air. Scaffolding or temporary dirt blocks help, and you can remove them when the shell is closed. If you are in creative mode, flying along the rim of each layer is the fastest way. In survival, plan the stacks first with the count shown above the picture.

Ellipsoids and flattened spheres

The Ellipsoid option accepts a width, a height and a depth. The same rule applies with three radii instead of one. A shape that is wide and short makes a good dome base or a flying saucer. A shape that is tall and thin is a rocket body or an egg. Keep the sizes close to each other in parity (all odd or all even) so the shape stays symmetrical around its centre.

Common mistakes

• Building a solid sphere by accident. Check that Hollow is selected unless you really want the filling.
• Skipping the layer below. The shell is only closed when each layer lines up with the previous one. Keep the faint outline switched on.
• Counting the equator twice. On an even diameter the two middle layers are identical. That is correct, not a mistake.
• Running out of height. Check the world height before you start. In Java Edition 1.18 and later the Overworld runs from Y -64 to Y 319, which is 384 layers. The Nether and the End are 256 layers.

Related generators

Half a sphere is a dome, so use the dome generator for roofs. The circle generator gives you any single layer as a flat outline, and the ring generator makes donuts. Convert the block total into stacks with the stack calculator.

Sources and notes

World height figures come from the Minecraft Wiki page on height limits, checked on 25 October 2026. The shapes are computed by the tool and are the same in every version. BlockShapes is not affiliated with Mojang or Microsoft.