ToolPetal
Nether portal calculator
- Runs on your device
- Nothing uploaded
- Free, no sign-up
Will my portals link?
Portal size and obsidian
How to use the nether portal calculator
- Find your coordinates. In Java Edition press F3 and read the XYZ line. In Bedrock, turn on Show Coordinates in the world settings.
- Type them in. Enter Overworld X, Y and Z to get the Nether spot, or type Nether numbers to get the Overworld spot. Both sides update as you type.
- Build at the result. Build your Nether portal at the Nether X and Z shown. Y can be any safe height.
- Check the link. Enter where both portals stand to see if each one leads to the other.
How Nether coordinates work
One block in the Nether equals 8 blocks in the Overworld, for X and Z. To go from the Overworld to the Nether, divide X and Z by 8. To go back, multiply by 8. Y is not divided. The tool rounds down to the block you stand in, so -1003 becomes -126 (exactly -125.375).
| Overworld X, Z | Nether X, Z |
|---|---|
| 0, 0 | 0, 0 |
| 800, -1600 | 100, -200 |
| 1000, -250 | 125, -32 (exactly -31.25) |
| -5000, 12000 | -625, 1500 |
How portal linking works
When you step through a portal, the game works out the matching spot in the other world and looks for an existing portal nearby. In Java Edition 1.16 and later it searches up to 16 blocks around the spot in the Nether and up to 128 blocks around it in the Overworld, and uses the closest portal it finds. If there is none, it builds a new portal. That is why a Nether portal built a little off the right spot can still link, while two Overworld portals close together may lead to the same Nether portal. Bedrock Edition searches in a similar way, but its ranges differ slightly.
Portal sizes and obsidian
The smallest portal has an opening 2 wide and 3 tall. It takes 10 obsidian, or 14 with the corners filled. The largest opening is 21 by 21, which takes 84 obsidian, or 88 with corners. The formula is 2 times (width plus height), plus 4 if you fill the corners. Corners are optional, so you can use any block there or leave them empty.
Questions
How do I convert Overworld coordinates to the Nether?
Divide the Overworld X and Z by 8. Y stays the same or can be any safe height. Overworld 1000, 64, -250 becomes Nether 125, 64, -32.
How do I convert Nether coordinates to the Overworld?
Multiply the Nether X and Z by 8. Nether 100, 70, -200 matches Overworld 800, 70, -1600.
Why did my nether portal not link?
The game only looks for a portal near the matching spot: 16 blocks in the Nether and 128 blocks in the Overworld in Java Edition. If your portal is further away, or another portal is closer, it builds or uses a different one.
How much obsidian do I need for a nether portal?
A standard portal needs 10 obsidian without corners or 14 with corners. A larger portal needs 2 times (width plus height) of the opening, plus 4 for corners.
What is the biggest nether portal?
The opening can be up to 21 blocks wide and 21 blocks tall, which needs 84 obsidian without corners.
Does the Y coordinate matter?
Not for linking. Y is not divided by 8, and the game finds portals above or below the spot. Just build the Nether portal at a safe height between the bedrock floor and roof.