I'm wondering if anyone has a simple way of calculating subtractive split times. For example, if you swim 100 Free and your time is 1:04.36, and the results show your split time as 31.62, is there a simple way to calculate what your time was for the 2nd 50? I know that on the USMS site, you can look up some of your results, and often these include subtractive splits, but this site does not list all meets. Is there a website that has a "calculator" for this purpose? Or does anyone know a way of programming something like Excel to calculate these?