How Far Apart Do Nether Portals Need to Be?

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By Bikash Roy

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Bikash Roy

Online Research Specialist · SEO Strategist · Web Developer

Bikash personally verifies every calculator against official standards (WHO, NIH, government data). Online research specialist, SEO strategist, and web developer with 10+ years building accurate digital tools.

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· August 16, 2026

Neither number is stated in game, but both fall directly out of two documented figures: the search radii, and the 1:8 ratio.

The two rules

Keep Overworld portals more than 128 blocks apart.

Keep Nether portals more than 16 blocks apart.

Break either and two portals compete for the same partner, and one of them appears to stop working.

Where 128 comes from

When you step into a portal in the Overworld, the game scales your coordinate by 1:8 and then searches a 16-block radius in the Nether for an existing portal.

So two Overworld portals will find the same Nether portal whenever their scaled positions are within 16 blocks of each other. Scaling back up:

16 Nether blocks × 8 = 128 Overworld blocks

Worked:

Twelve is inside the 16-block radius, so both Overworld portals will link to whichever Nether portal is there. The second portal you build will seem to have no effect at all.

Where 16 comes from

The return trip works the same way with the other radius. Leaving a Nether portal, the game multiplies by 8 and searches a 128-block radius in the Overworld.

Two Nether portals therefore return to the same Overworld portal whenever their mapped positions are within 128 blocks:

128 Overworld blocks ÷ 8 = 16 Nether blocks

Worked:

Eighty is inside the 128-block radius, so both Nether portals send you back to the same place.

Why it is really one rule

Both derivations describe the same 128-Overworld-block span, measured from opposite sides of the ratio. That has a useful consequence:

If your Nether portals are more than 16 blocks apart, your Overworld portals are automatically more than 128 apart.

So there is only one number to check, and it is easiest to check in the Nether, where the distances are smaller and the tunnels are already there. That is the basis of the layout in the nether hub planning guide.

Leave margin

Do not build to exactly 16. Three reasons:

1. Terrain moves portals. Lava, bedrock, and ravines force you a few blocks off the plan, and those blocks come out of your margin.
2. The radius is measured from the scaled coordinate, not from your portal, so errors at both ends compound.
3. Diagonal distance is not axis distance. Two portals 16 apart on X and 16 apart on Z are further apart in a straight line — but if either axis alone is inside the window, you are still at risk.

Space hub portals 24–32 Nether blocks apart. That is 192–256 Overworld blocks, still compact, with room to move.

When you want them to share

Sometimes linking is the goal. Two Overworld portals deliberately built within 128 blocks of each other will both route to a single Nether portal, which is a legitimate pattern for a base with several entrances that should all arrive at the same Nether stop.

It only becomes a problem when it is unintentional — which is usually when a new build goes up near an old portal months later.

Checking an existing setup

1. List your Nether portal coordinates.
2. Compare each pair on X and on Z separately.
3. Any pair under 16 on either axis is at risk.
4. Move one of them, or accept that they will share.

If a pair is already misbehaving, the diagnosis table in 6 nether portal mistakes that create duplicates will narrow down whether spacing is actually the cause — a portal that never linked in the first place looks identical from the outside, and the fix is different.

The nether portal calculator converts both directions if you want to check a set of coordinates quickly rather than dividing by hand.