Estimated Time Left Calculation in C#

 Stopwatch sw; long totaltime = 0; // counts the total time passed in milliseconds int secondsleft; // estimated time left int i = 0; // counter in the foreach loop // objList has couple of hundred elements  //secondsleft is recalculated after each iteration foreach (var obj in objList) { sw = Stopwatch.StartNew(); //some time consuming process here  i++; totaltime = totaltime + sw.ElapsedMilliseconds; secondsleft = (int) Math.Floor((double) totaltime / i / 1000 * (objList.Count() - i)); }