fractions

I need to express something (a horse's height in traditional form) as units of 'hands' = 4 inches. Using the FRACTIONS option is OK - it will convert decimal to 1/4 and 3/4 which is fine, but I would like Excel to reduce the 2/4 to 1/2. I tried CUSTOM but using the '2' units only gives 0, 1/2, or 1. Any suggestions, please?