I think by default it's like 70-80 but it's much more comfortable for me at least 90 pref 100.
Here you find a tutorial on how to change FOV.
://www nexusmods com/fallout4/mods/107/?
(add . in the open spaces)
You will need to fix the three ini files. It won't lock out achievements. I use it, and I still get achievements.
First file to modify is Fallout4.ini file which is found at C:\Users\[name]\Documents\My Games\Fallout4\
You need to add the following two lines to the file, under the directory named [Display]
fDefaultWorldFOV=XX
fDefault1stPersonFOV=YY
Replace XX and YY with your desired FoV (I use 100 which is fine for me)
Next file is FalloutPrefs.ini found in the same folder in My Games. Repeat the process.
Final file, is the Fallout4Prefs.ini in the steamapps\common\Fallout 4\Fallout4 folder (wherever you installed Steam)
Add the same two lines under display.
Remember to save each file, and you are good to go.
Console use does not negate achievements in FO4.
It did in FO NV