Instead of paying for ringtones in Apple's iTunes Store, you can easily turn any song you own already into a custom ringtone for your iPhone. Here's how to edit any song down to a suitable ringtone length (and select the most suitable section of the song), then turn it into a ringtone file in iTunes on your Mac. Finally, we show how to set it as a ringtone on your iPhone.
In this tutorial we use iTunes version 11 and iOS 7 on the iPhone, but the principle is largely the same for earlier software. To see the process in action, we've created a video of this tutorial, embedded below, but read on for more detail of each step.
Turn any song into an iPhone ringtone: Edit the selected song
Locate your chosen song in iTunes (we're going for 'Loner', by Burial). If it's not in your iTunes library already, you can drag the file on to the iTunes icon in your Dock.
Right-click the song, and select Get Info. Go to the Options tab of the dialogue box that pops up, and adjust the Start and Stop Times of the song, forcing it to only play a small excerpt (make sure your selected excerpt is less than 30 seconds, the maximum for a ringtone).
You may want to play through the song a few times to work exactly which bit of the song you want: if so, keep an eye on the elapsed time in the top screen and note down good moments to cut off. Once you're happy with the Start and Stop Times, click OK. The song will not play only that chunk when double-clicked - but the rest of the song is still there, and hasn't been deleted. Don't worry!
Turn any song into an iPhone ringtone: Create an AAC version of the song
Now we want to create a duplicate version of the track that only contains the section chosen above. You do this by right-clicking the track again, and this time selecting 'Create AAC Version'. After a brief processing delay you'll see that there are now two copies of the song with the same name, but one is much shorter - that's the new AAC version which we'll use for the ringtone.
(You should now go back into the original version of the song and untick the Start Time and Stop Time so that in future it plays normally, rather than only playing the sub-30-second excerpt we selected before.)
Create an AAC version of the song you want to turn into an iPhone ringtone...
...and now there are two songs. But the lower of the two is only 14 seconds long. That's our ringtone
Turn any song into an iPhone ringtone: Change the filename extension
Right-click the short version of the track and select 'Show In Finder'. This will give you access to the .m4a file (and will also help you to know which file to work on). You need to change this into a different file type so that iTunes knows it's a ringtone. Simply click the file name and change the extension to .m4r instead.
The Finder will ask if you're sure. Select 'Use .m4r' to confirm your choice. (Leave this Finder window open somewhere, because we'll be coming back to it in a moment.)
Turn any song into an iPhone ringtone: Delete the AAC from your music library
Before we import this file into iTunes' Tones folder, we'll go back into the Music library and delete the trimmed track. The two tracks have the same name so make sure you're deleting the short track, and not your longer original. Pick the option to Keep File - we want to remove the short track from our music library, but we need to keep the file itself, which we're going to use as an iPhone ringtone.
Turn any song into an iPhone ringtone: Import the .m4r file into Tones
Now go back to the Finder window and double-click the .m4r file; it should automatically open in iTunes, re-importing itself and appearing in the Tones library. If it doesn't, you can drag the file on to the iTunes icon in your Dock, or open the Tones folder and select File, Add to Library...
Can't find the Tones library in iTunes? It may not be visible because of the way you've got your settings. To check, go to iTunes, Preferences... Under the General tab, make sure the Tones box is ticked.
If 'Tones' in the top 'Show:' section isn't ticked, tick it, hit OK, and go back into your library. Select Tones from the dropdown menu at the top left. You should see your new ringtone there.
Turn any song into an iPhone ringtone: Sync with your iPhone
We're nearly there; we just need to get the ringtone on to the iPhone. Plug your iPhone into the Mac, and select its icon at the top right. Under the Tones tab, make sure you've ticked the box by 'Sync Tones'. Click Apply or Sync, and wait for iTunes to sync the iPhone, which is likely to take a few minutes. (But if you've set it to sync the music, video, apps and other files, this could take longer than that.) If you've got more than one tone in your iTunes Tones library you can tick 'Selected tones' and choose individual tones to sync.
When it's finished, eject the iPhone and unplug it from the Mac.
Turn any song into an iPhone ringtone: Set the new ringtone
Switch your iPhone on, and open the Settings app (it's the silver cog icon).
Scroll down and select the Sounds option (labelled with a red 'volume' icon), and you'll see a range of vibrate, ringer and alert options, with your currently selected ringtone at the bottom; below this are the tones used for new voicemails, texts and so on. Hit any you wish to change to the new ringtone and select it from the list. As you can see, it appears at the top of the list as a new option - it has the same name as the original song.
And that's it: the next time we take a call, everyone nearby will get a nice dose of melancholy drum and bass. Good luck.
See Also: How to Make Your Own Movie Trailer with iMovie on Mac