What is the class of 2020 current grade? How old they are? What is their birth year?

Answer 1

They'll be graduating next spring. They will be entering 12th grade, and will have their 17th birthday before Sept 1st. They were born between Sept 2001 and Sept 2002. (The cutoff month moves a month or two depending on the state, but always in the fall around the start of the school year)

Answer 2

Children come to ACS Doha from a wide range of countries and schools. ... and schools. The table below shows the equivalent class age and curriculum stage for different education systems for the academic year 2019-2020.