Nether Portal Calculator
Enter your Overworld or Nether coordinates to instantly find the matching portal location in the other dimension. The calculator also shows how many obsidian blocks you need to build a portal of any size, and how many Overworld blocks you save by traveling through the Nether instead of walking on the surface.
How the Nether portal coordinate formula works
Minecraft uses a fixed 8:1 scale between the Overworld and the Nether for horizontal distance. This means one block of travel in the Nether equals eight blocks of travel in the Overworld along the X and Z axes. To find the correct Nether location for an Overworld portal, divide the Overworld X and Z coordinates by 8. To find the Overworld location for a Nether portal, multiply the Nether X and Z by 8. The Y coordinate (altitude) is not scaled: it carries over unchanged between dimensions, so you can use it as a rough reference but you will usually need to choose a practical Y level for building.
Portal linking and how the game pairs portals
When you step into a portal for the first time, Minecraft searches a 128-block radius around the calculated target coordinates (in the destination dimension) for an existing portal to link to. If none is found within that range, the game creates a new portal at or near the calculated coordinates. This means two Overworld portals that are fewer than 1,024 blocks apart (128 x 8) can end up linking to the same Nether portal, causing players to emerge at the wrong location. To avoid this, keep Overworld portals at least 1,024 blocks apart, or equivalently at least 128 blocks apart in the Nether. When building a Nether highway, calculate each portal pair individually and confirm the Nether portals are spaced at least 128 blocks from each other.
Obsidian block count and portal construction
A Nether portal frame is built from obsidian and can range from a minimum of 4 blocks wide by 5 blocks tall (with a 2x3 interior opening) up to a maximum of 23x23 in any shape, as long as it forms a complete rectangle. The frame formula is: 2 x (width - 2) for the top and bottom rows, plus 2 x (height - 2) for the left and right columns, plus 4 corner blocks if you want a complete rectangle. Corner blocks are optional - the portal activates without them - but including them gives the frame a finished look and prevents accidental breaking. Obsidian cannot be obtained by mining unless you use a diamond or netherite pickaxe, so plan your resource gathering before you dig into the frame.
Travel savings and Nether highways
Because the Nether compresses horizontal distance by a factor of 8, it is used in nearly every large Minecraft world as a fast-travel network. A Nether highway is a path or tunnel connecting portal pairs in the Nether. Walking 100 blocks along a Nether highway corresponds to moving 800 blocks on the Overworld surface, so cross-continent journeys that would take many minutes on foot become quick trips through the Nether. This calculator shows you both the raw Overworld distance between two locations and the equivalent Nether route distance, so you can see immediately how much travel you save. The savings grow linearly: every 8 Overworld blocks of distance converts to 1 block of Nether walking.
Common portal frame sizes and obsidian cost
| Width x Height (inner) | Obsidian (with corners) | Obsidian (no corners) | Portal cells |
|---|---|---|---|
| 2 x 3 (minimum - 4x5 frame) | 14 | 10 | 6 |
| 3 x 3 (5x5 frame) | 16 | 12 | 9 |
| 3 x 4 (5x6 frame) | 18 | 14 | 12 |
| 4 x 5 (6x7 frame) | 22 | 18 | 20 |
| 5 x 5 (7x7 frame) | 24 | 20 | 25 |
| 4 x 4 (6x6 frame) | 20 | 16 | 16 |
Inner dimensions shown. All values include 4 corner blocks. The game allows any size from 4x5 up to 23x23.
Frequently asked questions
What is the Overworld to Nether coordinate ratio?
The ratio is 8:1 for the X and Z axes. One block traveled in the Nether equals eight blocks in the Overworld. Divide Overworld X and Z by 8 to get the Nether coordinates; multiply Nether X and Z by 8 for the Overworld equivalent. The Y axis is not scaled and stays the same in both dimensions.
How do I stop my portals linking to the wrong location?
The game looks for an existing portal within 128 blocks (in the destination dimension) of the mathematically calculated target point. If two Overworld portals are fewer than 1,024 blocks apart, their Nether coordinates are fewer than 128 blocks apart and the game may link them to the same Nether portal. Keep Overworld portals at least 1,024 blocks from each other, or make sure their Nether counterparts are at least 128 blocks apart and built before the portals are first activated.
How many obsidian blocks does a Nether portal need?
A standard minimum portal (4 wide, 5 tall with corners) uses 14 obsidian. Without corners it uses 10. Larger portals follow the formula: 2 x (width - 2) + 2 x (height - 2) + 4 (for corners). The maximum portal size is 23x23, which needs 172 obsidian with corners. Use this calculator's obsidian section to get the exact count for any size.
Does Y coordinate matter when converting between dimensions?
No, Y is not part of the 8:1 scaling. The game does not translate the Y coordinate: it simply tries to place the exit portal at a practical Y level near the target XZ location. In the Nether you should usually build portals between Y=30 and Y=100 to stay above the lava sea floor and below the bedrock ceiling. In the Overworld, most surface portals sit around Y=64.
Can I use a Nether portal in any game mode?
Nether portals work in Survival and Adventure mode. In Creative mode they also work by default. In Hardcore mode they behave the same as Survival. Portals cannot link to the End dimension - that dimension uses its own separate portal structure found in Strongholds.
What is the maximum size of a Nether portal?
The maximum is 23 blocks wide by 23 blocks tall (outer frame dimensions), giving a 21x21 inner opening. The minimum is 4 wide by 5 tall (2x3 inner opening). Any rectangular shape within those limits will activate as a portal when lit with a flint and steel or fire charge.
Why does my portal come out at the wrong place?
This usually happens because the game found an existing portal closer to the target coordinates than the one you built, so it linked to that instead. Check that no other portal in your world is within 128 Nether blocks (or 1,024 Overworld blocks) of the intended destination. You can also destroy the incorrect link by removing the rival portal and re-entering yours to force a new link to the correct one.