Android get free size of internal/external memory

I want to get the size of free memory on internal/external storage of my device programmatically. I'm using this piece of code :

StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
long bytesAvailable = (long)stat.getBlockSize() *(long)stat.getBlockCount();
long megAvailable = bytesAvailable / 1048576;
Log.e("","Available MB : "+megAvailable);

File path = Environment.getDataDirectory();
StatFs stat2 = new StatFs(path.getPath());
long blockSize = stat2.getBlockSize();
long availableBlocks = stat2.getAvailableBlocks();
String format =  Formatter.formatFileSize(this, availableBlocks * blockSize);
Log.e("","Format : "+format);

and the result which I'm getting is :

11-15 10:27:18.844: E/(25822): Available MB : 7572
11-15 10:27:18.844: E/(25822): Format : 869MB

The problem is that I want to get the free memory of SdCard which is 1,96GB right now. How can I fix this code so I can get the free size ?

Below is the code for your purpose :

public static boolean externalMemoryAvailable() {
        return android.os.Environment.getExternalStorageState().equals(
                android.os.Environment.MEDIA_MOUNTED);
    }

    public static String getAvailableInternalMemorySize() {
        File path = Environment.getDataDirectory();
        StatFs stat = new StatFs(path.getPath());
        long blockSize = stat.getBlockSizeLong();
        long availableBlocks = stat.getAvailableBlocksLong();
        return formatSize(availableBlocks * blockSize);
    }

    public static String getTotalInternalMemorySize() {
        File path = Environment.getDataDirectory();
        StatFs stat = new StatFs(path.getPath());
        long blockSize = stat.getBlockSizeLong();
        long totalBlocks = stat.getBlockCountLong();
        return formatSize(totalBlocks * blockSize);
    }

    public static String getAvailableExternalMemorySize() {
        if (externalMemoryAvailable()) {
            File path = Environment.getExternalStorageDirectory();
            StatFs stat = new StatFs(path.getPath());
            long blockSize = stat.getBlockSizeLong();
            long availableBlocks = stat.getAvailableBlocksLong();
            return formatSize(availableBlocks * blockSize);
        } else {
            return ERROR;
        }
    }

    public static String getTotalExternalMemorySize() {
        if (externalMemoryAvailable()) {
            File path = Environment.getExternalStorageDirectory();
            StatFs stat = new StatFs(path.getPath());
            long blockSize = stat.getBlockSizeLong();
            long totalBlocks = stat.getBlockCountLong();
            return formatSize(totalBlocks * blockSize);
        } else {
            return ERROR;
        }
    }

    public static String formatSize(long size) {
        String suffix = null;

        if (size >= 1024) {
            suffix = "KB";
            size /= 1024;
            if (size >= 1024) {
                suffix = "MB";
                size /= 1024;
            }
        }

        StringBuilder resultBuffer = new StringBuilder(Long.toString(size));

        int commaOffset = resultBuffer.length() - 3;
        while (commaOffset > 0) {
            resultBuffer.insert(commaOffset, ',');
            commaOffset -= 3;
        }

        if (suffix != null) resultBuffer.append(suffix);
        return resultBuffer.toString();
    }

Get RAM Size

ActivityManager actManager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
MemoryInfo memInfo = new ActivityManager.MemoryInfo();
actManager.getMemoryInfo(memInfo);
long totalMemory = memInfo.totalMem;

This is the way I did it :

StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
long bytesAvailable;
if (android.os.Build.VERSION.SDK_INT >= 
    android.os.Build.VERSION_CODES.JELLY_BEAN_MR2) {
    bytesAvailable = stat.getBlockSizeLong() * stat.getAvailableBlocksLong();
}
else {
    bytesAvailable = (long)stat.getBlockSize() * (long)stat.getAvailableBlocks();
}
long megAvailable = bytesAvailable / (1024 * 1024);
Log.e("","Available MB : "+megAvailable);