Nether Coords is a Fabric client side mod that provides players with easier ways of determining relative coordinates in game. Because Nether Coords is a client-side mod it works in both Singleplayer and Multiplayer and does not need to be installed on the server, just on the client.

Commands:

/portal - Get coords for a portal at your location
/portal [x] [y] [z] - Get coords for a portal at a block position
/portal <dimension> [x] [y] [z] - Get coords for a portal at a block position in a specific dimension
/portal help - displays an in-game help message.

Default keybind for Nether Coords is F8!

Nether Coords is a Fabric Only mod that requires the Fabric Loader and the Fabric API