Nether portal calculator: Overworld and Nether coordinates, both ways
Convert Overworld and Nether coordinates as you type, check where a pair of portals really leads, and keep a list of your named portals.
One block in the Nether is eight blocks in the Overworld, which makes the Nether the fastest way to travel, as long as your portals lead where you want. This calculator converts coordinates both ways as you type, warns you about heights where a portal is a bad idea, and checks where a pair of portals will really take you, using the same search the game does.
How to use it
- Press F3 in Java Edition (or turn on Show Coordinates in the world settings of Bedrock Edition) and note the X, Y and Z where your Overworld portal is or will be.
- Enter them under Overworld. The Nether coordinates appear as you type; it works the other way too.
- Go through your portal, travel in the Nether to the coordinates shown, and build the Nether portal there. Copy puts X Y Z on the clipboard, ready for a sign or a /tp command.
- Already have both portals? Turn off Convert as I type, enter where each one really is, and read Where the portals lead.
- Give the pair a name and save it. Saved portals stay in this browser and take part in the check, so you can see when two pairs are too close.
How the conversion works
Going into the Nether, X and Z are divided by 8 and rounded down: Overworld X 1,000 and Z −300 become Nether X 125 and Z −38. Coming back, they are multiplied by 8. Y is never scaled, so a portal at Y 70 in the Overworld looks for its partner around Y 70 in the Nether, which is often inside netherrack; the game then finds the nearest place it can build.
How portals link
When you step into a portal, the game converts your position and looks for an existing portal in the other dimension near that point, over the whole height of the world. In Java Edition it searches 16 blocks each way in the Nether and 128 blocks each way in the Overworld. Bedrock Edition searches 128 blocks each way in both. If it finds several portals, it takes the closest one in a straight line, counting the difference in height. If it finds none, it builds a new portal within 16 blocks of the point, on solid ground if it can, or on a small obsidian platform if it cannot.
That is why linking can go one way only. A Nether portal 20 blocks from the exact spot is outside Java's 16-block search, so entering the Overworld portal builds a new Nether portal. But coming back from that first Nether portal, the Overworld search reaches 128 blocks and finds your original portal, so it seems fine in one direction.
Why portals link to the wrong place
- The Nether portal is not at the converted coordinates. Build it within a few blocks of the exact spot, at a similar height.
- Two Overworld portals are less than about 128 blocks apart (Java). Their Nether points are only 16 blocks apart, so they can share or swap Nether portals. Keep Overworld portals well apart, or build their Nether portals exactly at the converted points.
- Height counts. A portal on the Nether roof can be closer in a straight line than one on the ground, or the other way around.
- A ghast broke the Nether portal. When you come back through the Overworld side, the game no longer finds it and builds a new one. Relight the old one, then remove the new one.
- In Bedrock Edition, the 128-block search in the Nether makes portals far more likely to share. Place Nether portals exactly where the calculator says.
Heights to watch in the Nether
The Nether has a bedrock floor from Y 0 to 4, a lava sea up to Y 31 and a bedrock ceiling from Y 123 to 127. In Java Edition you can build on top of the roof up to Y 255, and roof portals link like any other, but the game never builds a new portal higher than Y 118, so build roof portals yourself. Bedrock Edition's Nether stops at Y 127.
Questions
Why does the Nether portal not appear exactly at the coordinates?
The game looks for a free, solid place near the converted point and may place the portal up to 16 blocks away, at another height. Move it to the exact spot if you want the pair to link reliably, and break the one the game made.
Are the numbers the same in Bedrock Edition?
The conversion is: divide by 8 going in, multiply by 8 coming back. The search for existing portals is wider in Bedrock Edition, and its Nether is lower, so choose the edition above to get the right warnings and checks.
Everything happens in this page, and your saved portals stay in this browser. For your next build, see the stack calculator, the enchantment order calculator and all tools.