What your result means
The grid is a top-down plan of one layer of your build: every filled square is one block, every empty square is air. Blocks needed is how many blocks that single layer costs, and stacks converts it into full stacks of 64 plus the remainder, which is what you actually carry in your inventory. If you are building a tower or silo, multiply the block count by the number of layers — a 15 × 15 ring repeated 20 blocks high needs 40 × 20 = 800 blocks. If the layers should curve instead of stacking straight, the Minecraft sphere generator works out each ring for you.
A grid cannot draw a curve, so it fakes one
Minecraft has no diagonal blocks, so every circle is really a staircase of straight runs. The trick is choosing where those steps fall: put them in the wrong place and the shape reads as an octagon or a wobbly blob rather than a circle.
This generator tests the centre of each block against the true circle and keeps only the blocks whose centres fall inside it, then strips the interior to leave a one-block ring. That is why the steps come out even and mirror-symmetrical in all four quadrants — and why odd widths (9, 15, 25, 49, 101) look cleaner than even ones: an odd width has a single centre column to build outwards from.
How it works
Every block position is treated as a point on a grid and tested against the equation of an ellipse. Blocks whose centre falls inside the ellipse are kept; the rest become air. For an outline, a kept block only survives if at least one of the four blocks it touches falls outside the shape — that leaves a single-block ring. A thick outline tests all eight neighbours instead, closing the diagonal gaps some players dislike. A filled disc keeps everything inside the shape. Because the test is symmetrical, the top half always mirrors the bottom and the left half mirrors the right, so you can build one quarter and copy it.
How to use this calculator
- Type the width in blocks. With Keep it a perfect circle on, the height follows automatically.
- For an oval or a dome footprint, switch the toggle off and set a different height.
- Choose a style: outline for rings, walls and lighthouse tops; thick outline if you want no diagonal gaps; filled for floors, platforms and roundabouts.
- Read the block count and stack count before you start mining, so you gather enough material in one trip.
- Build row by row using the blocks per row list, or copy the grid as text and keep it on a second screen.
Formula
x and y are the block’s column and row, counting from zero at the top-left corner. W and H are the width and height of the grid in blocks. Adding 0.5 tests the centre of the block rather than its corner, which is what keeps the curve even. Dividing by W/2 and H/2 scales the grid so the shape fits exactly; when W equals H this is the equation of a circle, and when they differ it is an ellipse. Any block satisfying the inequality is inside the shape.
Example calculation
A 15 × 15 circle — the most common size for a lighthouse or silo — with the outline style:
Blocks per row: 5, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 5
Outline total ≈ 40 blocks
Filled total ≈ 177 blocks
Stacks needed (outline) ≈ 0 stacks + 40 blocks
The widest row is the middle one at 15 blocks across, but only 2 of those are placed — the leftmost and rightmost. The 5 blocks in the top row are the flat cap of the circle. Set the generator to 15 × 15 and you will see exactly these numbers.
Frequently asked questions
Why do even-numbered circles look lopsided?＋
An even width has no middle column — the centre of the circle falls on the seam between two blocks, so the flat top and bottom are two blocks wide and the shape reads slightly squarer. Odd sizes such as 9, 15, 25, 49 and 101 have a true centre block, which is why most builders stick to them.
What is the biggest circle I can generate?＋
500 blocks wide and 500 tall. That is far larger than most builds need — a 500 × 500 outline works out at 1,412 blocks for a single layer — but it covers full-chunk-aligned projects and large terraforming jobs.
Does the block count include the layers above?＋
No. The count is for one flat layer. Multiply it by your build height to get the total: a 25 × 25 outline is 68 blocks per layer, so a 10-block-high wall needs 680 blocks, plus anything for the floor or roof.
Related calculators
Assumptions & limitations
Every figure here comes from a simplified model. Keep these limits in mind when reading your result:
- The grid is a single flat layer viewed from above. Vertical builds need the count multiplied by their height.
- Blocks are treated as unit squares with no thickness variation, so slabs, stairs and fences are not modelled — those can smooth a curve further than a full-block grid allows.
- Circle geometry is version-independent, but block counts assume every position is filled with one full block; scaffolding, supports and lighting are not included.
- Very large grids (above roughly 250 × 250) are too big to copy as text and are best read from the on-screen preview.