What Is the Nether Portal Calculator?
In Minecraft, the Nether is compressed relative to the Overworld: every block you travel in the Nether equals 8 blocks in the Overworld. This 1:8 ratio applies to the horizontal X and Z axes. The Nether Portal Calculator converts coordinates between the two dimensions so your portals link to each other instead of generating a brand-new portal in the wrong place.
How to Use It
Pick a direction — Overworld → Nether or Nether → Overworld — then enter the X, Y, and Z coordinates of your existing portal. The calculator returns the matching coordinates where you should build the paired portal. The Y (height) coordinate is unaffected by the ratio and stays the same in both dimensions.
The Formula Explained
The conversion only touches the horizontal axes:
Overworld → Nether: \(X \div 8\) and \(Z \div 8\).
Nether → Overworld: \(X \times 8\) and \(Z \times 8\).
For accurate linking, build the destination portal within about 16 blocks (horizontally) of these target coordinates so the game pairs them.
Worked Example
Suppose your Overworld portal is at X = 800, Y = 64, Z = -400. Dividing the horizontal axes by 8 gives:
$$X_{n} = \frac{800}{8} = 100 \qquad Z_{n} = \frac{-400}{8} = -50 \qquad Y_{n} = 64$$while Y stays 64. So build your Nether portal near (100, 64, -50).
FAQ
Does Y change between dimensions? No — only X and Z are divided or multiplied by 8. Y stays identical.
How close does the destination need to be? Build within roughly 16 blocks horizontally of the calculated coordinates to guarantee the portals link.
Why do portals sometimes not link? If there is no existing portal within range, the game creates a new one. Building at the exact calculated spot prevents this.
