Minecraft pixel circle / oval generator
Set a diameter, or an independent width and height for an oval, pick a thin or thick outline (or fill the whole disk), and get a block grid template with exact block counts — the kind of circle chart Minecraft builders (and builders in other blocky voxel games) have traced out by hand for years. Download it as a PNG when you're happy with it.
How the rasterisation works
There is no built-in "draw a circle" primitive for a grid of square blocks, so every circle-chart generator, this one included, is implementing a rule for deciding which cells count as inside the shape. The rule here is the same distance test used by the long-running community circle charts:
Step 1 — inscribe an ellipse in the box
Given a width w and height h, the centre of the shape sits at ((w−1)/2, (h−1)/2) in cell coordinates, and the two radii are rx = w/2 and ry = h/2. For a circle, w equals h and the two radii are equal.
Step 2 — test each cell's centre
For a cell at column x, row y, compute the normalised distance from the centre and keep the cell if it lands at or inside the ellipse:
Every cell that passes is part of the filled disk. That set alone is what "Fill (disk)" draws.
Step 3 — find the boundary for the outline
A filled cell counts as part of the thin outline if at least one of its four orthogonal neighbours (up, down, left, right) is not in the disk — including neighbours that fall off the edge of the grid entirely. The thick outline adds the four diagonal neighbours to that same test, which fills in the single-block pinch points a thin ring leaves where the boundary turns a tight diagonal corner.
Small diameters round to solid squares, and that's expected. At diameter 1, 2 or 3 every cell in the box is close enough to the centre to pass the test, so the "circle" is indistinguishable from a filled square. A block grid can only start looking distinctly round once there is enough room for the corners to actually get cut — in practice from around 5–7 blocks across.
Why an even diameter looks different from an odd one
An odd-diameter box has one exact centre row and centre column, so the shape has a true axis of symmetry through the middle of a block, and it can come to a single-block point at the top, bottom, left and right. An even-diameter box has no centre cell — the symmetry axis falls on the seam between two cells — so those four extremes render as flat two-block edges instead of a point. Neither is more "correct"; they are the two ways a continuous circle can land on a discrete grid.
See the size chart for exact block counts across a range of common diameters, all produced by this same formula.
Using the template to build
- Pick a diameter (or an independent width and height for an oval) and a thin or thick outline, or turn on fill for a solid disk.
- Use the grid on screen as a map: each square is one block. Count rows down from the top and columns in from the left to find where a filled cell sits, then place your build's block in the matching spot in-game.
- For a ring, build one full row before moving to the next — it is much easier to keep your place scanning the template left to right, top to bottom, than to jump around.
- Download the PNG if you'd rather work from a saved image than the live page, or want to paste it into a build-planning document.
- Stack the same footprint through as many vertical layers as you need for a sphere, a cylinder wall, or a dome — this tool draws one flat layer; repeating it (and shrinking it toward the poles, for a sphere) is the next step, outside what a single 2D template can show.
Common sizes at a glance
A handful of frequently-used diameters, thin outline. The full table — including thick-outline and filled counts up to 101 blocks — is on the size chart page.
| Diameter | Outline blocks (thin) | Filled (disk) blocks |
|---|---|---|
| 5 | 12 | 21 |
| 9 | 24 | 69 |
| 15 | 40 | 177 |
| 21 | 56 | 349 |
| 31 | 84 | 749 |
| 51 | 144 | 2053 |
Use cases & limitations
Where this is genuinely useful
- Planning a circular wall, tower base, or window in Minecraft (or any other blocky voxel game) before laying a single block. Seeing the whole footprint at once catches an asymmetry or a size that's too small for the space long before you're three layers in.
- Getting the block count for a materials run. The outline and filled counts tell you exactly how many blocks one layer of a ring or a disk needs, so you know how much to gather first.
- Comparing thin vs thick before committing. A thin ring uses fewer blocks and reads as a cleaner line from a distance; a thick one reads as sturdier up close and has no single-block diagonal pinch points. Toggle between them on the same size before you decide.
- Ovals for arches, domes, and non-circular windows. Unlinking width and height covers shapes a pure circle chart can't.
What this tool cannot tell you
- Height / how many layers to stack. This draws one flat layer. A sphere, dome or cylinder wall needs this footprint repeated (and, for a sphere, shrunk) across multiple layers — that planning happens outside a single 2D template.
- Which block or texture to use. The grid tells you shape and count, not material — that choice is yours.
- The one "true" circle for a size. As covered above, the inside/outside test is a convention, not a law. A different generator using a different rule can produce a handful of different boundary cells at the same diameter and still be a legitimate blocky circle.
Frequently asked questions
Why isn't there one single "correct" pixel circle for a given diameter?
Because a circle is a smooth curve and a block grid is not — any method for deciding which square cells count as "inside" is a judgement call, not a law of geometry. This tool tests whether the centre of each cell falls inside the ellipse inscribed in the width × height box, which is the same rule most circle-chart generators use. A different rule (for example, testing whether the majority of a cell's area is inside) can shift a handful of boundary cells one way or the other, especially at small sizes. Both are "correct" blocky circles; they are just different valid roundings of the same curve.
What's the difference between the thin and thick outline?
Thin keeps a ring one block wide: a filled cell counts as edge if any of its four orthogonal neighbours (up, down, left, right) is outside the shape. Thick adds the four diagonal neighbours to that test too, so a cell that only turns a corner diagonally — no orthogonal neighbour is empty, but a diagonal one is — gets included as well. That fills in the single-block "pinch points" a thin ring leaves on tight diagonal turns, which is why some builders prefer it for a sturdier-looking wall.
Why do small circles look blocky and large ones look smoother?
The curve's radius grows linearly with diameter, but a block is always exactly one block wide, so each step in the staircase becomes a smaller fraction of the whole shape as the circle gets bigger. A 7-block circle is almost all corner; a 65-block circle has the same kind of corners, they are just proportionally tiny next to the long straight-ish runs between them. Nothing about the algorithm changes — only how noticeable the discretisation is at that scale.
Can I make an oval, or only a circle?
Both. Turn off "Circle (link W/H)" and the width and height fields become independent — set a wider width than height (or the reverse) and the tool rasterises an ellipse inscribed in that box using the same inside/outside test it uses for a circle. There is a Swap button to flip the two if you picked them the wrong way round.
How is the block count worked out, and will it match what I place in-game?
The outline count is every cell the tool marks as edge (thin or thick, whichever is selected); the filled count is every cell inside the disk regardless of outline setting. Both are exact counts of the grid actually drawn on the canvas — there is no separate "in-game" number, because the template is the plan: if you place one block per filled cell in the pattern shown, you will use exactly that many blocks. The one thing this tool cannot know is your build's height (how many layers you stack the ring or disk), so multiply by that yourself for a total block count in a real build.
What's the largest circle this can generate?
128 blocks in each dimension. That is a practical ceiling for a page rendered on a canvas at readable cell sizes, not a limit of the underlying maths — the same distance test works at any size. If you need a specific very large diameter for a build, the reference chart page lists counts up to 101 blocks, and the formula above lets you compute further sizes by hand.
Why does an even diameter look different from an odd one of a similar size?
An odd diameter has a single centre row and centre column of cells, so the shape has a true axis of symmetry running through the middle of a block — it tends to come to a single-block point at the top, bottom, left and right. An even diameter has no centre cell; the axis of symmetry falls on the boundary between two cells, so those four extremes are flat two-block edges instead of a single point. Both are symmetric and both are valid circles at that size — they are just two different ways a continuous circle can land on a discrete grid.
Does this only work for one specific game?
No. The output is a generic block grid — rows and columns of filled or empty cells — that applies to any voxel or tile-based building game where you place one unit per cell. It is described here in terms a blocky voxel game's builders will recognise because that is the most common use case, but nothing about the rasterisation is specific to any one title.
Do I need an account, and is the PNG download free?
No account, no sign-up, and the download is free with no watermark. The grid is drawn on a canvas element in your browser and exported to a PNG file locally — what you set here never leaves your device to produce that file.