API UnitLevel

Returns the unit's level.

/script SendChatMessage("Level "..UnitLevel("target"));

If the current target is a Level 50 mob, this macro will print Level 50 in your chat window. If the unit's level is unknown, i.e. a Level ?? target, or is a special boss, UnitLevel will return -1.

Details

 * Note that the value returned by UnitLevel("player") will most likely be incorrect when called in a PLAYER_LEVEL_UP event handler, or shortly after leveling in general. Check PLAYER_LEVEL_UP arg1 for the correct level.