When the LHC started running at the end of March 2010--after a 14-month shutdown for major repairs--one of the main objectives was reaching a luminosity of 10[superscript 32] cm [superscript -2] s [superscript -1] by the end of 2010. On 13 October 2010 that goal was achieved. One important parameter to take into account to reach this luminosity is the number of protons that are circulating in both directions around the large hadron collider. The aim of this article is to introduce a simple approximation of how the number of protons travelling in the LHC near the speed of light can be counted. (Contains 4 figures.)