How to use the Nether portal calculator
Find your coordinates
On Java, press F3 (Fn + F3 on many laptops) and read the XYZ line. On Bedrock, turn on Show Coordinates in the world settings.
Stand in your portal and enter them
Use the spot where your Overworld portal is, or where you want it. You can paste the whole F3 line into the calculator.
Build the other portal at the result
Go through, travel to the calculated coordinates in the Nether, and build and light a portal there at a similar height.
Check the link
Add both portals, and any others nearby, to the link checker to confirm they pair up.
How Nether coordinates work: the 1:8 ratio
Every block in the Nether matches 8 blocks in the Overworld along X and Z, which is why the Nether is used for fast travel. Height is not scaled.
- Overworld → Nether: divide X and Z by 8 and round down. Keep Y.
- Nether → Overworld: multiply X and Z by 8. Keep Y.
| Overworld | Nether |
|---|---|
800 64 -1600 | 100 64 -200 |
1000 70 250 | 125 70 31 |
-37 64 12 | -5 64 1 |
How Nether portals choose where to link
When you step through a portal, the game converts your position to the other dimension, then looks for existing portals in a square around that spot. It picks the closest one in 3D, counting height, and the lower portal wins a tie. If there is none, it builds a new portal within about 16 blocks of the target.
| Searching in | Java | Bedrock |
|---|---|---|
| Overworld | 128 | 128 |
| Nether | 16 | 128 |
Why your portal links to the wrong place, and how to fix it
- The other portal is not at the converted coordinates. Rebuild it at the spot the calculator gives you.
- The heights are very different. Distance includes Y, so a portal 40 blocks higher can lose to one further away at the right height.
- Two portals share one partner. Overworld portals close together can convert to spots near the same Nether portal. Give each its own portal at its own converted coordinates.
- The game made a new portal on your first trip. Break the one it generated once you have built yours in the right place.
- A portal is not lit. Only active portal blocks count; relight it with flint and steel.
Planning a Nether hub
A Nether hub is a central area with tunnels out to each base's portal. Convert every base's Overworld portal, build its Nether portal at those coordinates, and connect them with straight tunnels. Because each portal sits exactly where the game looks first, every trip lands where you expect. Shared hubs are a staple of SMP servers, where a whole community travels through one network.
How much obsidian you need for a Nether portal
The smallest portal is a 4×5 frame around a 2×3 opening. It takes 10 obsidian if you skip the corners, which are optional, or 14 with them. The biggest, a 23×23 frame, takes 84 (88 with corners). Use the obsidian calculator for any size in between.
How to build and light a Nether portal
- Build an upright obsidian frame at least 4 blocks wide and 5 tall. You need a diamond or netherite pickaxe to mine obsidian, or you can make it in place by pouring water onto still lava.
- Light the inside of the frame with flint and steel or a fire charge.
- Step in and wait a few seconds to travel. The first trip may generate a partner portal; replace it with one at your calculated coordinates.
Nether portal questions
How do you calculate Nether coordinates?
Divide your Overworld X and Z by 8 and round down; Y stays the same. Overworld 800, 64, -1600 becomes Nether 100, 64, -200. To go the other way, multiply the Nether X and Z by 8.
What is the Nether to Overworld ratio?
1:8 horizontally. Every block you walk in the Nether covers 8 blocks in the Overworld along X and Z. Height (Y) is not scaled.
Why did my Nether portal link to the wrong portal?
The game converts your position, then looks for existing portals around that spot and uses the closest one, measured in 3D including height. If the portal you wanted is not built at the converted coordinates, or sits at a very different height, another portal can be closer and wins. Build each portal at the calculated coordinates and a similar Y level.
How far apart do Nether portals need to be?
There is no fixed minimum, because the closest portal always wins. Trouble starts when a portal has no partner at its converted coordinates: in Java, an Overworld portal then uses any Nether portal within 16 blocks of its target, and a Nether portal uses any Overworld portal within 128 blocks of its target. Bedrock searches 128 blocks in both dimensions.
How much obsidian do you need for a Nether portal?
At least 10 obsidian for the smallest portal (a 4×5 frame without its corners), or 14 with the corners filled in. The largest portal, a 23×23 frame, takes 84 obsidian, or 88 with corners.
Does the Y level matter for Nether portals?
Y is not divided by 8, but it does count when the game picks the closest portal. A portal far above or below the target can lose to one that is further away horizontally but at the right height.
Do Nether coordinates work the same on Bedrock?
The 1:8 conversion is the same on Bedrock and Java. The difference is the search area: Bedrock looks 128 blocks around the target in the Nether as well as the Overworld, while Java only looks 16 blocks in the Nether, so wrong links in the Nether are more common on Bedrock.
How big can a Nether portal be?
Frames can be anything from 4×5 (a 2×3 opening) up to 23×23 (a 21×21 opening), in either direction.