1. Navigate to settings. For many devices you can get to settings by swiping down from the very top of the screen and touching the gear symbol. Some devices have a physical settings button near the home and back buttons.
2. Inside settings, find the About Device section. This is normally very near the bottom of the options, under the System section, on devices with tabs, it may be under the More tab.
3. Once in About Device, look for Android version. This number is your Android version, e.g.: 4.4.2