Build guide
Best uses
This generator is useful for arches, tunnel mouths, bridge supports and curved entrances. The planner gives a block-by-block shape plan and material total before you start placing blocks in your world.
How to build it
Start with the centre line, build one side of the arc, then mirror it across the line. A half-circle plan is easier to check before you add wall height.
Planning tip
Use outline for an arch frame and filled mode for a solid decorative wall.
Before you start
Choose the final outside dimensions, check whether the centre is 1×1 or 2×2, and gather the stack total shown by the tool. For large builds, use the printable layer or quadrant plan instead of trying to follow a giant grid on one screen.
Turn a half circle into a usable arch
Set the full width first, then keep the flat base line level. That line is the opening for a tunnel, bridge or gate. Build one side of the curve from the centre or edge, confirm the headroom, then mirror the pattern. Repeat the finished arch backward only after the front frame looks right.
Choose depth after the shape is correct
A one-block outline is a guide, not a finished tunnel. Add wall thickness after the curve is symmetrical. This makes it easier to use stone, deepslate, wood or stairs without hiding a mistake in the basic arch.
Plan the opening before the wall
Measure the opening that must fit below the arch before choosing its diameter. A tunnel for a player, rail line or bridge path needs more than a curve that merely looks round. Mark the flat base line, test the headroom with temporary blocks, then copy the finished outline through the required wall depth.
Use the curve as a structural guide
Once the basic arch is symmetrical, add stairs, slabs or trim one side at a time and mirror the detail. This keeps the decorative layer from hiding an uneven frame.
FAQ
Does this work in Java and Bedrock?
Yes. These are manual block-placement blueprints, so the visual plan works in both editions.
Can I export the plan?
The Shape Planner supports JSON and CSV layer exports. PNG, SVG and print exports are available for compatible 2D blueprints.
More build questions
How do I make a half circle for an arch?
Choose a diameter, use the centre line as the flat base, then build the curve from one side and mirror it across the centre.
Can I use a half circle for a tunnel?
Yes. Outline mode is useful for tunnel frames and filled mode can help plan a solid decorative entrance.
This is also a Minecraft arch generator for tunnel mouths, bridge curves and rounded entrances. Use the flat centre line as the base of the arch.
What size half circle is best for a tunnel?
Choose a width that leaves enough headroom for the player, rails, mounts or a road. Test the base opening before repeating the arch through wall depth.
Can I use stairs on a half-circle arch?
Yes, but establish the normal block frame first. Test stair direction on one side, then mirror the decoration across the centre line.