The 10/40 window is a rectangular piece of geography that holds the world’s deepest spiritual and physical needs. It is a designated belt that extends from West Africa and across Asia, between 10 degrees and 40 degrees north latitude.   
  

Within the 10/40 window are 62 countries with a total population of 3.1 billion or 97% of the world’s least evangelised population. 84% of these people are the world’s poorest. Only 27% of the world’s missionaries work within this region.