How Many Football Fields Would the Monarchs Cover? Example: Using the 2007/2008 population estimate of 4.6 hectares, here is our calculation: 1 football field is roughly 1 acre. (The exact measurements of football fields vary.) 1 hectare = 2.417 acres 2.417 football fields in 1 hectare 4.6 hectares of monarchs 4.6 X 2.417 = 11.11 football fields of monarch trees this year Just think: Monarchs from across eastern North America cover an area the size of only 11 football fields!     This Season Teachers Kids Orientation Registration Search Copyright 1997-2008 Journey North. All Rights Reserved. Questions or comments? Contact us.