About

Independent planning tools for Minecraft builders.

Sealmount is a fan-made website. The aim is modest: a little help so the next hour in-game is a little more fun. Plan a build, take the results with you, and get back to playing. Calculations run on your device, with no account required.

Sealmount is operated by Aaron. For questions about the site, contact support@sealmount.com.

What is Sealmount?

Sealmount is a free, fan-made website with five Minecraft planning tools for Java and Bedrock players:

• Circle Generator: circles, ovals and round towers from 3 to 300 blocks across, planned row by row.
• Pixel Art Generator & Editor: turns a picture into a wall or floor of concrete, wool and terracotta, up to 256 × 256 blocks.
• Nether Portal Calculator: divides Overworld X and Z by 8 and rounds down for the Nether; Y stays the same.
• Beacon Calculator: a full level-4 pyramid takes 164 mineral blocks, and it plans shared bases for up to 5 × 5 beacons.
• Sphere & Dome Generator: spheres and domes from 3 to 256 blocks across, planned layer by layer from the bottom.

Every page is available in ten languages: English, Simplified Chinese, Traditional Chinese, German, Russian, Japanese, Korean, Spanish, Brazilian Portuguese and French. The tools need no account and nothing to install; they run in your browser, and your pictures, plans and building progress are not uploaded.

Sealmount is not an official Minecraft service and is not approved by or associated with Mojang or Microsoft.

Who this is for

You already know what you want to build. You do not want a wiki tab, a spreadsheet, and a Discord screenshot open at the same time. If one page saves you a miscount or a ruined wall, that is enough.

Languages and translations

Our team is just one person, who speaks some English and some Chinese. The German, Russian, Japanese, Korean, Spanish, Portuguese and French pages are bound to contain some translation mistakes. Thank you for your patience.

If a word, a sentence or a game term looks wrong, please let us know. Every report makes the page a little better for the next player. Report a translation problem

How the calculations work

Circle and oval blueprints

Circle Planner uses Sealmount's square-grid approximation: a cell is filled when its centre falls inside the chosen ellipse. A hollow ring keeps the outer outline; extra thickness adds outlines inward. The material total is the number of filled cells multiplied by the wall height. This is one practical way to draw block circles, not an official Minecraft shape rule. It uses full blocks only.

Automated checks reconstruct the footprint from the written row instructions as well as checking its counts. Those checks run during development; they are not a substitute for placing the blocks in Minecraft.

Pixel art from a picture

Image conversion and manual edits create one-block-thick walls or floors using a fixed 49-material palette of concrete, wool and terracotta. Tiles, material totals, resource plans and exports all use the same edited pixels.

Nether coordinates

The portal calculator divides X and Z by 8 and rounds down when going to the Nether; on the return trip it multiplies X and Z by 8. Y stays unchanged. The Java/Bedrock selector changes the command syntax; it does not change the rounding rule. These coordinates are a planning target, not a guarantee of a safe landing or a particular portal link.

Command references: Mojang's Java execute-in notes and Microsoft's Bedrock execute documentation. The Overworld-to-Nether conversion uses the floor division described above.

Beacon materials

The beacon calculator adds the area of every solid pyramid layer. For a beacon footprint w × d, layer k below the beacons uses (w + 2k) × (d + 2k) base blocks. Material totals cover the base; beacon blocks and activation items are separate. Displayed effect-range and refresh notes use Java values.

Minecraft's official recipe guide explains beacon crafting, bases and activation. The totals and shared-base calculations follow the layer formula on this page, rather than a table supplied by that guide.

Sphere and dome blueprints

The sphere and dome generator uses Circle's centre rule in three dimensions: a block is placed when the centre of its cell lies inside the ellipsoid set by the width, depth and height. A dome is the upper half of such a shape, centred on its bottom layer. That bottom layer is exactly the Circle tool's footprint for the same width and depth, so a dome fits on a round tower planned with Circle. A dome with an odd width and a height of (width + 1) ÷ 2 is exactly the top half of the sphere with that width, middle layer included.

A hollow shell keeps every block whose distance to the outside, counted in steps across block faces without diagonal steps, is no more than the chosen thickness. That leaves no gap through which the inside shows. A dome's open base does not count as outside, so the bottom layer of a hollow dome is a ring, not a filled disc. A solid shape keeps every block inside. Layer 1 is the bottom layer, and empty layers or rows are skipped. Width and depth run from 3 to 256 blocks, height goes up to 256, and shells are 1 to 16 blocks thick. It uses full blocks only.

The Circle generator and the Sphere and dome generator are now one tool: choose Circle, Dome or Sphere on either page, so a dome on a round tower is planned in one place.

What has been checked

Calculation and browser checks: automated checks cover grid construction, material arithmetic and command formatting. Browser checks cover the controls and result actions. These checks are separate from testing a build or command inside Minecraft.

The Sphere and dome generator was added on 12 October 2026. Automated checks cover its layer shapes, block counts, closed hollow shells and the match between a dome's bottom layer and the Circle footprint. Its blueprints have not yet been built and checked in Java or Bedrock.

Pixel art's Java and Bedrock structure downloads are experimental. The exported builds have not been checked inside Minecraft.

The .litematic and .mcstructure structure files from Circle, Sphere and dome, and Beacon are checked automatically by reading them back, but have not yet been loaded in Java or Bedrock.

In-game use: the site operator has used Circle, Nether portal and Beacon as building guides in Minecraft and found the plans usable for construction. Older releases, server plugins and add-ons may behave differently.

Structured Java and Bedrock checks still need to be recorded case by case, including teleport-command execution, portal pairing, and beacon effects and timing.

This page is the current public record of what has been checked. If an output looks wrong, send a bug report with the tool and what you expected.

Page reviewed 27 October 2026. In-game checks remain limited to the cases described above.

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