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