Choose a song or audio file you want to use
Make sure the audio is in a supported format, such as MP3, M4A, or AAC
Trim the audio to 30 seconds or less
On Mac, open Music and import the file
On Windows, open iTunes and import the file
Set the start and stop times for the clip
Convert the clip to AAC format
Change the file extension from .m4a to .m4r
Transfer the .m4r file to your iPhone using Finder, iTunes, or AirDrop
On iPhone, open Settings
Tap Sounds & Haptics
Tap Ringtone
Select the custom ringtone from the list
Use the ringtone for calls, texts, or alerts as needed