Custom ringtones help set your smartphone apart from the M4R and ringtone files found on Apple's iPhone smartphone. To place a ringtone on an Android device, however, it must be in MP3 format. There are a number of applications and websites -- including iTunes, Miro VideoConverter and Online-convert.com -- that allow you do convert M4R files to MP3 format.
Locate the M4R file on the computer's hard drive and click on the file to highlight it. Click on the file a second time to bring up the name edit box. Change the file's file extension from "m4r" to "m4a." Click anywhere on the computer's desktop to see the new file extension.
Launch iTunes and drag the new M4A file to the iTunes window.
Click the "Edit" menu and select the "Preferences..." option. Click the "General" tab, followed by the "Import Settings..." button. Click the arrow to the right of the "Import Using" heading and select the "MP3 Encoder" option from the drop-down menu. Click the "OK" button to save the changes.
Right-click on the M4A file you added to the iTunes application in Step 2 and select the "Create MP3 Version" option from the context menu. ITunes creates an MP3 version of the file and saves it on the computer.
Open a Web browser and navigate to Online-convert.com. Click the arrow beneath the "Audio Converter" heading and select the "Convert to MP3" option from the drop-down menu.
Click the "Choose File" button and locate the M4R file on the computer's hard drive. Highlight the file and click the "Open" button.
Click the "Convert File" button. Online-convert.com converts the file into MP3 format and saves it onto your computer's hard drive.
Open a Web browser and navigate to MiroVideoConverter.com. Click the "Download Miro VideoConverter" button to download the install file onto the computer, then double-click the install file and follow the on-screen instructions to install the program on the computer.
Double-click the "Miro VideoConverter" application icon to launch the application. Drag the M4R file onto the Miro VideoConverter application window.
Click the arrow to the right of the "Pick a Device or Video Format" heading and select your Android device from the drop-down menu. If your device is not listed, select the "MP3" option instead.
Click the "Convert!" button to convert the file and save it on the computer's hard drive.