Java tutorial
//package com.java2s; import android.os.Environment; import android.os.StatFs; public class Main { public static long getAvailableStorage() { String storageDirectory = null; storageDirectory = Environment.getExternalStorageDirectory().toString(); try { StatFs stat = new StatFs(storageDirectory); long avaliableSize = ((long) stat.getAvailableBlocks() * (long) stat.getBlockSize()); return avaliableSize; } catch (RuntimeException ex) { return 0; } } }