One of the key issues in Alberta’s ongoing teachers’ strike is class sizes, but it’s difficult to put precise numbers on just how large classes have become because the province no longer collects that data specifically.
Alberta used to publish class size data annually, detailing the number of students in every class at more than 1,500 schools across the province.
In 2019, the newly elected UCP government put an end to that practice.
The following year, the government also changed the per-student funding formula for school boards, which had tied funding growth to enrolment growth on an annual basis, in favour of a three-year “weighted moving average” (WMA) instead.
Larger school boards in fast-growing cities in particular have lamented the new formula since it was announced in February 2020.
“It means our funding will be based on the numbers of students we’ve had in our classrooms in previous years,” Trisha Estabrooks, who served as chair of Edmonton Public Schools, said at the time.
“In essence, it’s sort of like looking in the rearview mirror and we can never catch up.”
The change took effect in September 2020, in the depths of the COVID-19 pandemic, which saw a brief period of declining enrolment.
This was followed by a surge in enrolment, but because the new formula uses previous years’ enrolment figures as part of its calculations, numerous school boards received less money than they would have under the previous formula.
Complaints about the formula have continued, year after year.
“This new WMA funding model benefits school divisions with declining enrolments, often found in rural areas,” the Elk Island Public Schools authority, operated out of Sherwood Park, explained in a presentation from January 2025.
“For school divisions with increasing enrolment, the WMA model creates a funding shortfall.”
Exactly how this new funding formula has affected class sizes, however, is difficult to quantify since the Alberta government stopped collecting class size data the year before it changed the formula.
But it’s still possible to get a rough idea of how much Alberta’s teaching staff has grown compared to how much student enrolment has grown since the change was introduced.
As part of its annual budget documents, the provincial government publishes the number of “certificated staff” working for school boards in terms of full-time equivalent positions. These numbers provide a sense of how many teachers are working in the province.
It’s not a perfect measure, as not all certificated staff necessarily work directly with students in classrooms, and there’s no breakdown of teaching staff by city, let alone by school, let alone by class.
But it at least lets us see, in broad terms, how growth in certificated staff compares to growth in enrolment at a provincewide level. (The Alberta government still publishes enrolment figures annually.)
When we compare these two figures, we can see that teaching staff and student enrolment tended to track pretty close to one another until about 2021.
From that point on, a gap emerges, with enrolment growth outpacing growth in teaching staff.
That gap has persisted through to the school year that ended in 2025, the most recent for which enrolment figures are available. (Those figures are still preliminary and subject to revisions.)
Overall, by these measures, student enrolment has grown by 15 per cent since 2016-17, while teaching staff has grown by just eight per cent.
Darryl Hunter, a professor of educational policy studies at the University of Alberta, reviewed this analysis of the available data and cautions that it, alone, does not demonstrate the change in funding formula caused the gap between student enrolment and teaching staff.
“As you know, correlations are not equal to causation,” he said.
“You can point out that these happen to coincide … but whether it caused it is just another question altogether.”
School board officials, however, have had no problem in the past directly tying the WMA formula to increases in class sizes and funding shortfalls.
“This funding model is not in the best interest of students,” Edmonton Public Schools trustee Dawn Hancock said in May 2024. “And I hope that our government sees it and makes a change.”
The following year, the government did just that.
As part of its 2025-26 budget, the provincial government revealed a new, two-year weighted average to replace the three-year formula.
The three-year formula calculated average enrolment by looking at the previous year (which received a 20-per-cent weight), estimates for the current year (30-per-cent weight) and projected enrolment for the following year (50-per-cent weight).
The new, two-year formula includes just the current year (30-per-cent weight) and projected enrolment for the following year (70-per-cent weight).
“Moving to a two-year [calculation] is our attempt to hopefully strike the right balance to be able to get dollars to fast-growing school divisions in a much faster way, and also provide as much long-term stability as we possibly can to smaller school divisions,” Education Minister Demetrios Nicolaides said in March.
The Ministry of Education did not respond by deadline to a request for comment on this story.
The new formula takes effect for the 2025-26 school year.
Alberta School Councils’ Association president Ken Glazebrook described the change as “a positive first step.”
“It’s well-known that the classrooms are crowded and there’s been limited resources,” said Glazebrook, whose organization advances parent perspectives and promotes dialogue between families and school officials.
“We’ll acknowledge that the government has tried to rectify part of that problem with changing the weighted moving average down to two years from three years.”
The 2025-26 budget also included the hiring of an estimated 1,045 new full-time-equivalent certificated teaching staff, which represents a 2.7-per-cent increase over the previous year.
For the Alberta Teachers’ Association (ATA), however, this doesn’t go far enough.
The ATA wants the government to do more to address what it describes as accumulated shortfalls in the number of working teachers in the province.
ATA president Jason Schilling has said more than 5,000 new teachers are required to reach the pupil-teacher ratios recommended in a provincial report from 2003, which was published in the wake of the last major teachers’ strike in Alberta.
Does class size impact student academic performance?
While Alberta cancelled its detailed class-size reporting in 2019, Edmonton Public Schools still tracks this data, which suggests class sizes in many schools remain much larger than the recommendations in that 22-year-old report.
Anecdotes from teachers, students and parents in other school divisions also suggest class sizes exceed those recommendations, but precise figures are harder to come by.
Hunter, with the University of Alberta, said it would be “immensely helpful” to have the type of detailed class size data that the province used to gather and publish annually.
“It might cause a bit of angst to put some of the stuff out in the public domain but, hey, we do live in a democracy,” he said.
“Student-teacher ratio is a key performance indicator for any system … and people want to know what these numbers are.”
