Java tutorial
//package com.java2s; import android.os.Environment; import android.os.StatFs; public class Main { public static long getSdCardFree() { long l = 0L; if (Environment.getExternalStorageState().equals("mounted")) { StatFs statfs = new StatFs(Environment.getExternalStorageDirectory().getPath()); l = ((long) statfs.getBlockSize() * (long) statfs.getAvailableBlocks()) / 1024L / 1024L; } return l; } }