Bexley Grammar School is a co-educational selective Academy of approximately 1400 students, including 400 in the Sixth Form.  It draws on the top 30% ability range of students from a largely working-class catchment area.  73% of pupils from the 10 wards that contribute the greatest proportion of the school's pupils are from areas where below 13% of adults have a higher education qualification (compared to the average in England of 19.2%).  9.3% of pupils are eligible for free school meals, which is a relatively high percentage for a selective school.   The percentages of pupils from ethnic minority households and those whose first language is not (or believed not to be) English are 49% and 20% respectively and both fall above the 60th percentile nationally.

All Sixth Form students at Bexley Grammar School follow the International Baccalaureate Diploma Programme.  The threshold for admission to the 6th form is 44 points at GCSE and the current Year 13 cohort includes about 60 students who joined from other, mainly non-selective, schools in South East London.  The average achievement of the most recent IB cohort was equivalent to 185 UCAS points, or 3A* grades at A level. The average IB point score per student was 33 and the average point score per subject was 5.25.  IB subject predictions are closely based on students’ Autumn term report grades, 95% or more of which are regularly within one point of the final grade.