Age Grading: how it works

Age grading uses tables of "age factors" and "age standards" to put all runners, 
regardless of age and sex on a level playing field. In particular, they allow 
runners' performances, no matter what their age, to be corrected to what they 
would have been achieving in their prime years, and permit valid comparisons to 
be made between people of different ages.
  
 
       >100% = World record level
       > 90% = World class
       > 80% = National class 
       > 70% = Regional class
       >  0% = An Athlete