Some students and educators in Calgary high schools say class sizes are too large this fall.

Calgary public schools are putting more than 40 students in a classroom, and one local guidance counsellor tells CBC News there is a class with more 50.  

The Calgary Board of Education will release official numbers at the end of this month, but some students and educators are already complaining.

"I see definitely a large increase in the number of students in every class. This year is particularly bad," said Derek Duijur-Mclean, a Grade 12 student at Queen Elizabeth High School. 

He said he is feeling a little overcrowded in some of his courses.

"Definitely in math and biology I'm seeing high 30s, low 40s, which is unusual because you shouldn't really have more than about 30 kids anyways."

Frank Bruseker, president of Alberta Teachers Union Local 38, says teaching staff are already feeling stretched. He said 50 students is rare, but 40 is very common.

"High schools are seeing this year the same number of students but with seven fewer teachers in each of those schools."

Duijur-Mclean worries that supersized classes may affect the quality of his education.

"You know it was definitely nicer a couple of years ago — we'll just put it like that — to not have this many kids in a class."

The Calgary Board of Education says it's heading for a record enrolment this year as initial numbers indicate about 3,300 more students are in the system.

Those numbers are for students from kindergarten to Grade 12, as well as outreach programs, homeschooled kids and Chinook Learning Services.