C# - FormatFileSize

gistfile1.cs

        static string FormatFileSize(long value, string format = null)
        {
            var multipliers = new string[] { "o", "Kio", "Mio" };
            var midx = 0;

            while ((Math.Abs(value) >= 1024) && (midx < multipliers.Length))
            {
                value /= 1000;
                ++midx;
            }

            var unit = multipliers[midx];

            return string.Format("{0} {1}", value.ToString(format ?? ""), unit);
        }