MC BUILD PLANNERMinecraft building guide
Use the centre line as the base. Mirror the curve.
Half circles are useful for tunnel entrances, bridge arches, windows, gates and decorative roof openings. The reliable method is to choose the full diameter, keep the flat centre line level, and build one side of the curve before mirroring it.
The half-circle diameter is the full width from one end of the arch to the other. Pick a size that leaves enough headroom for the tunnel, bridge or entrance. Odd widths give one middle block at the top of the curve; even widths create a centre guide between blocks.
Small windows, compact gates and decorative arches.
Tunnel mouths, bridge spans and main entrances.
Large gates, cathedral openings and server landmark bridges.
Use outline for a frame or thicker walls when the arch needs structural weight.
Place the two end points of the opening first, then mark the middle of the span. The centre line is the reference for both sides of the arch. If the opening has a door or tunnel floor, build that flat line before adding the curved blocks above it.
Follow the half-circle blueprint from the centre outward or from one end inward. When one side looks correct, repeat the same stepped pattern on the opposite side. This is safer than alternating random blocks from both ends.
A two-dimensional half circle becomes an arch when you repeat it through the wall thickness. Build the front outline first, then copy it backward for the chosen depth. Add stairs, slabs or decorative blocks only after the main block frame is symmetrical.
A half circle needs a level diameter line. Without it, the curve can drift upward or become an uneven tunnel opening.
Stairs can make an arch look smoother, but place normal blocks first. Decorative orientation is easier after the main shape is correct.
Leave headroom for the player, mounts, rails or a road. Test the opening at ground level before building the full wall depth.
Yes. Use the half-circle plan as the front opening, then repeat it through the tunnel depth. Outline mode is useful for the structural frame.
Use the Half Circle Generator or generate a full circle and build only one half above the centre line. The dedicated tool makes the intended opening easier to read.
Yes. The blueprint is manual block placement and works in Java and Bedrock.