Background photo - U.S. #5 Pikes Peak CO.

   This website is primarily about climbing by bike.  We have chosen to use an objective index to quantify and rank climbs - The Fiets Index (developed by the Dutch cycling magazine Fiets).  This index is described very well at RideWithGPS).  The actual formula is:    [H^2/D*10] + (T-1000:1000; but only if greater than 0)

    H = ending elevation minus starting elevation in meters. 

    D = total distance traveled in meters.  

    T = Height in meters. 

    ^ = multiply that number by itself (i.e., square the number) 

    * = multiply

    Note:  Only add T-1000 if that number is greater than zero.

​An example of the formula:  Using our Garmin ride data from our June 8, 2014 Mauna Kea climb: 

  1. Ending elevation = 13,821 feet which converts to 4,213 meters.
  2. Starting elevation is approximately 100' which converts to 30.5 meters. 
  3. 4,213 - 30.5 = ​4,182.5 ​[this is the "H" part of the formula]
  4. 4,182.5 x 4,182.5 = ​17,493,306 [This is the part of the formula where "H" is squared]
  5. Next:  convert the distance of the climb (43 miles) to meters:  69,201. [This is the "D" part of the formula]
  6. Multiply 69,201 x 10 = 692,010. [This is the D x 2 part of the formula]
  7. Divide 17,493,306 by 69,201 = 25.28 
  8. If the climb is greater than 1,000 meters (it is at 4,182.5):  4,182.5 - 1,000 = 3,182.5 [This is the "altitude bonus" , or "T" part of the formula]
  9. Divide 3,182.5 by 1,000 = 3. 
  10.  Add the base FIETS Index (25.28) to the height premium (3) = Mauna Kea FIETS Index 28.28

We created a spreadsheet to calculate the climb index, but for our chart, we used the formula embeded in the excellent riding gps site  .  RideWithGPS has a function that automatically calculates the FIETS Index for any route plotted on their website.  Here is the link for the example of that for Mauna Kea.  (note that our hand calculation is a bit different than the automatic calculation of RideWithGPS but that is likely because of the common variant between using websites to plot rides as compared to the actual on-road data we capture off our GPS devise during the ride (truly, we are just not sure which is most accurate, but they are very, very close - within 2%;  the FIETS index in RideWithGPS is located to the right of the map under the heading "metrics.")