Download and install the latest version of iTunes on your computer.
Get an MP3 file prepared on your desktop or any other location of choice.
Prepare your iPhone and an available USB cable.
After that, you can follow these steps to handle the MP3 to ringtone convert task. The process is divided into six steps, each of which will be detailed below.
Step 1. Add the MP3 files to iTunes
The very first step is to add the MP3 files to iTunes. To do this, launch your iTunes and click the “File” tab from the top right of iTunes’s window, then select “Add to Library…” Locate the place where your MP3 file stores and choose the song you wish to import.
Step 2. Trim the MP3 file
In your iTunes, click the “Songs” tab in the left panel. Then, right-click the MP3 file you imported from the computer. From the drop-down list, select “Song Info,” then “Options.” Check the box next to the start and stop, then input the start and stop times of the track, which should be within 30 seconds. (You can note the time of starting and ending in advance) Finally, click “OK” to finish the trim process.
Step 3. Convert the MP3 file to an AAC file
In iTunes, click the “File” tap in the upper left corner. From the drop-down list, select “Convert,” then select “Create AAC Version.” After that, you will see a new song appears in your iTunes library in a shorter time.
Step 4. Rename the AAC File
After converting the MP3 file to AAC format, you’ll get a new file followed by m4a, which is not the Apple ringtone format. Therefore, you’ll need to convert the m4a file to m4r, a ringtone format supported by Apple. Here’s how: in the “Songs” section on your iTunes, right-click the modified track and select “Show in Windows Explorer.” Press “F2” on your keyboard to change its extension to m4r.
Note: If you can’t see the extension, you can click the “View” tab on the ribbon, then check the box next to the “File name extensions” option to show the file extension.
Step 5. Sync the AAC file to your iPhone
Once you complete the renaming process, drag and drop the renamed file to your Desktop or any other folder on your computer. Then, plug your iPhone into the computer with a USB cable and click “Devices” in iTunes. From the extended section, choose “Tones,” and then drag the m4r file to the “Tones” section. If a drag-and-drop doesn’t work, try copying and pasting instead. After that, click “Sync” to pass the ringtone to your iPhone.
Step 6. Set the sound as your ringtone
On your iPhone, go to the Settings app. Scroll down to find " Sounds & Haptics," then “Ringtone.” Choose the custom sound as your ringtone.