Java tutorial
//package com.java2s; import java.util.Locale; public class Main { public static String formatBytes(long bytes) { int unit = 1024; if (bytes < unit) return bytes + " B"; int exp = (int) (Math.log(bytes) / Math.log(unit)); String pre = ("KMGTPE").charAt(exp - 1) + ""; return String.format(Locale.ENGLISH, "%.1f %sB", bytes / Math.pow(unit, exp), pre); } }