BlockJig

Nether portal calculator for Minecraft

Enter a portal's coordinates to find where its partner belongs. Overworld X and Z divide by 8 going to the Nether and multiply by 8 coming back, and Y stays the same.

Unofficial. Not affiliated with Mojang or Microsoft.

Overworld

1 square = 200 blocks

Nether

1 square = 25 blocks
Build the Nether portal at 100, 70, -200

The numbers above are an example, not your world. Replace them with your own coordinates from your game's position display.

Portal link search area

Saved portals

Save portals from both sides and each one shows which portal it links to. They are saved in this browser.

    How to link two portals

    1. Stand in your first portal and read its block coordinates.
    2. Type them into the side you are standing in. The other side fills in.
    3. Build the partner at the result, in the other dimension, before you walk through. A correctly placed portal stops the game from building a new one somewhere else.
    4. Save both here. If a portal's row warns about the return trip, one of your portals is closer than the one you meant to use.

    The rules the game uses

    RuleJavaBedrock
    Overworld to NetherX ÷ 8 and Z ÷ 8, rounded downSame
    Nether to OverworldX × 8 and Z × 8Same
    Y levelNot changedNot changed
    Search in the Overworld128 blocks each way128 blocks each way
    Search in the Nether16 blocks each way128 blocks each way
    If several portals are in rangeThe closest wins, measured in a straight line including height

    Game version: the wiki describes the current game. On 2026-11-01 the latest Java release on Mojang's version list was 26.3. We did not check the Bedrock version number, and we have not tested these rules in the game.

    Source: minecraft.wiki, Nether Portal, read 2026-11-01. The calculation follows these documented rules, and game updates can change them. It reads your numbers only: it has not seen your world, so terrain and portals you haven't saved aren't counted.

    Planning a round room around the portal? The circle generator gives the block plan.

    Questions

    How do you calculate nether portal coordinates?

    Going to the Nether, divide Overworld X and Z by 8 and round down, so X 800, Z -1600 becomes X 100, Z -200. Coming back, multiply Nether X and Z by 8. Y stays the same both ways.

    Do Y coordinates matter for nether portals?

    Y is not converted, but it counts. The game picks the closest portal in a straight line including height, so a portal at the wrong height can lose out to one further along X or Z.

    How far apart do nether portals need to be?

    To keep two Overworld portals from sharing a Nether partner in Java, keep their Nether partners more than 16 blocks apart along X or Z, which is about 128 blocks in the Overworld. Save them here to check for crossed links.

    Why did my portal go to the wrong place?

    Usually another portal was closer to the target than the one you built, or the partner was outside the search area so the game made a new one. Save both portals here and read what each one links to.

    How big is a nether portal?

    The smallest frame is 4 blocks wide and 5 tall, with the 4 corners optional, so 10 obsidian is the minimum. Frames can be larger, up to 23 by 23.

    Is this calculator official?

    No. BlockJig is an independent site, as the statement at the foot of each page says.

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