According to the Ministry of education website in 2017-2018, the last year where data was available, there were 125,979.93 full time equivalent (FTE) teachers, consisting of 83,742.24 elementary and 42,237.69 secondary teachers. As of 2017-2018 the number of students in Ontario was: 2,020,301
That works out to a ratio of 16.03 students per classroom teacher.
Under the new proposal 3,475 teaching positions disappear leaving122, 504 teachers, If the student numbers stay roughly the same, that works out to 16.49 students per teacher. Students counts have been fairly stable around 2.1 Million for the last 15 years
When the McGuinty government was elected in 2003 there were 2,129,742 students and 104,822 teachers for a ratio of 20.31 students per teacher.