To make a song into an iPhone ringtone, you need to convert the file into an ".m4r file" and then add it back onto your phone. You must own the song and have an iTunes account to be able to do this.
- Pick the song
Find the song you want to use as the ringtone in iTunes. Right-click the song and select Get Info. Under the Options tab, choose the section of the song you want by using the start time and stop time boxes. The average length for a ringtone is about 30 seconds. A text tone probably needs to be shorter.
- Convert the song
Right click on the song again and choose Create AAC Version. If that option isn't available, go to Preferences, and under the General tab, choose Import Settings and change the import settings to AAC. Right click on the new AAC version, and choose Show in Windows Explorer. In Windows Explorer, right-click the song and choose Rename. Rename the file type from ".m4a" to ".m4r."
- Add the song
Add the new ".m4r" file to iTunes. It now shows up in the Tones section. Go to the Tones section, and drag and drop the tone onto your phone. Select Settings on your iPhone, and scroll down to Sounds. Select either Ringtone or Text Tone to change either.