The 8:1 rule
Every block you travel in the Nether counts as 8 blocks in the Overworld, horizontally. To find matching coordinates:
- Overworld → Nether: divide X and Z by 8 and round down.
- Nether → Overworld: multiply X and Z by 8.
- Y (height) stays the same in both directions.
Example: an Overworld portal at X 1000, Z −2400 matches a Nether portal at X 125, Z −300. Rounding down matters for negative numbers: −100 ÷ 8 = −12.5, which becomes −13. The Nether portal calculator does this for you.
Step by step: linking two portals
- Build and light your Overworld portal. The frame needs to be at least 4 wide and 5 tall (10 obsidian without corners). Light it with flint and steel or a fire charge.
- Write down its coordinates. Stand in the portal and press F3 in Java, or turn on "Show Coordinates" in Bedrock world settings.
- Convert them with the 8:1 rule or the calculator.
- Go through the portal. The game may create a portal for you in the Nether, but not always in the right spot.
- Travel to the converted coordinates in the Nether and build a new portal there, ideally at a similar Y level to your Overworld portal.
- Break the portal the game made if it is in the wrong place, so it cannot interfere.
- Test it: walk through your new Nether portal. You should come out of your original Overworld portal.
How the game picks a portal
When you step through a portal, the game converts your position to the other dimension and searches around that point for an existing portal:
| Java Edition | Bedrock Edition | |
|---|---|---|
| Search area in the Overworld | 128 blocks around the target | 128 blocks around the target |
| Search area in the Nether | 16 blocks around the target | 128 blocks around the target |
| Height searched | Full world height | Full world height |
| Which portal wins | The closest one in straight-line distance, including height | |
If no portal is found, the game builds a new one near the target, looking for a safe spot within 16 blocks. If it cannot find one, it forces a portal at the target coordinates with a small obsidian platform.
The small Nether search area in Java is why linking feels unreliable: a portal you built 20 blocks away from the right spot simply will not be found, and the game makes yet another one.
Fixing a portal that links wrong
You come out at the wrong Nether portal
Another Nether portal is closer to the converted coordinates than yours. Either move your portal to the exact coordinates, or break the portal that is stealing the link.
You come back to the wrong Overworld portal
This usually happens when two Overworld portals are less than 128 blocks apart. Their Nether coordinates are less than 16 blocks apart, so they can share one Nether portal. Build a separate Nether portal at the exact converted coordinates for each Overworld portal, and keep the Nether portals apart from each other.
A new portal keeps appearing
Your Nether portal is outside the 16-block search area. Check your math, especially the rounding of negative numbers, and rebuild at the exact spot.
Building a Nether hub
Because of the 8:1 ratio, a tunnel of 125 blocks in the Nether covers 1,000 blocks in the Overworld. Many players build a central hub near Nether X 0, Z 0, with straight tunnels to each base's portal. Convert every base's coordinates with the calculator, dig tunnels along the X and Z axes, and add an ice boat road for even faster travel.
The Nether has a bedrock roof starting around Y 123, so build your tunnels and portals below that. A Potion of Fire Resistance makes digging through the Nether much safer.