Java tutorial
//package com.java2s; import java.io.File; import android.os.Environment; import android.os.StatFs; public class Main { public static long getSdCardAvailableSize() { File sdcardDir = Environment.getExternalStorageDirectory(); StatFs sf = null; try { sf = new StatFs(sdcardDir.getPath()); } catch (Exception e) { return 0; } long blockSize = sf.getBlockSize(); long availCount = sf.getAvailableBlocks(); return availCount * blockSize; } }