How Nether Portals Link: The 8:1 Rule and Why They Go Wrong

The 8:1 coordinate rule

Walking one block in the Nether covers eight blocks in the Overworld. According to the Minecraft Wiki, going from the Overworld to the Nether divides X and Z by 8 and rounds down, and going the other way multiplies X and Z by 8. The Y coordinate does not change.

Rounding goes toward negative infinity. An Overworld X of −239 is −29.875, which becomes −30. The calculator on this site shows each step.

Building a linked pair on purpose

To link two portals deliberately, pick the Overworld portal first, convert its X and Z, and build the Nether portal at those coordinates. Keep the Y level similar, because the game compares the full distance, including height.

You do not need to be exact. The game looks for the closest existing portal in a square area around the destination, so landing within a few blocks of the target is fine. The wiki gives the Overworld search as a 256×256 square, a 128-block radius, in both editions.

Search areas: Java vs Bedrock

The size of the area differs by edition and dimension. The wiki lists these figures as squares, not circles, centered on the converted coordinates and covering the full height.

• Java Edition, searching the Overworld: 256×256 blocks (128-block radius).
• Java Edition, searching the Nether: 32×32 blocks (16-block radius).
• Bedrock Edition, searching either dimension: 256×256 blocks (128-block radius).

What happens when nothing is found

If no portal is inside the area, the game builds a new one. Per the wiki, it looks for a suitable spot within 16 blocks horizontally of the destination, with any vertical distance. If it cannot find a good spot, it forces a portal at the destination and builds a small obsidian platform.

This is the most common cause of surprise portals. Two portals that look close in the Overworld can be too far apart in the Nether, especially in Java Edition, where the Nether search is only 16 blocks around the destination.

Why portals link to the wrong one

When several portals fall inside the search area, the game picks the closest by distance in the new coordinate system. That distance includes height, so a portal that looks farther away horizontally can still win if its Y level is closer.

A few other things can confuse the link.

• Portals built too close together in the Overworld map to the same few blocks in the Nether, so they can all share one Nether portal.
• A very wide portal can end up connected to more than one portal on the other side.
• In Java Edition, if the destination portal faces a different way, you can exit through what feels like the wrong side.
• A destroyed or deactivated portal is skipped, so the game may build a new one.

A tip for keeping links clean

Because of the 8:1 rule, Overworld portals only 8 blocks apart land one block apart in the Nether, so keep portals well apart if you want each to keep its own partner. Write down the coordinates of each portal, and convert them before you build. The nether portal calculator on this site checks whether two portals fall inside each other’s search area for both Java and Bedrock.