Ontario Top 6 Average: Repeats, Summer School, Rounding
Every Ontario university admits you on a number built from six Grade 12 courses, and almost everyone gets the basic rule right. The seats are lost on the edge cases: a prerequisite at 74 you assumed would drop out, a repeated course counted the way you did not expect, a summer-school mark that arrived too late, an 84.9 that was never going to be an 85. Here is the whole calculation, the exceptions school by school, and two worked examples with real numbers.
The base rule in one paragraph
Take every Grade 12 course you have taken at the U or M level. Put the courses your program requires into the six first, whatever their marks. Fill the remaining slots with your highest other U/M marks. Average the six with equal weight. That number is your admission average. Waterloo’s wording is the cleanest version of the rule: the admission average is “the average of your top six Grade 12 courses (U or M courses for Ontario students)” including the courses required for the program (Waterloo, What is an admission average?). Queen’s says the same thing from the other direction: the calculation “is based on prerequisite subjects, plus the next best 4U/M courses, for a total of 6 courses” (OUInfo, Queen’s).
Everything below is a footnote to that paragraph. Most of the footnotes are worth a mark or two. A few of them are worth a seat.
Which courses count
The fifth character of an Ontario course code tells you the level. U is university preparation (ENG4U, MHF4U, SCH4U). M is university/college preparation (BAT4M Accounting, BOH4M Business Leadership, PLF4M Recreation Leadership). Both count toward the six. C (college), O (open, including OLC4O) and E (workplace) do not, and neither does co-op. Waterloo states it plainly for Ontario students: “C (college), O (open), and co-op courses are not used when calculating your admission average,” and U of T says “the co-op component of Grade 12 courses will not be used for admission purposes” (U of T, Canadian high schools). A co-op placement attached to a U course still leaves you with the U mark; the placement credits themselves are invisible to the average.
Two limits on M courses. First, an M course can never stand in for a named U prerequisite: MCF3M is not MCR3U, and a Grade 12 M course is not a substitute for MHF4U. Second, Queen’s caps how many M courses you can lean on. Its published minimum is six 4U/4M courses with at least three at the 4U level, one of them ENG4U (Queen’s, Ontario high school). A schedule built from ENG4U plus five M courses is a valid OSSD and a problem at Queen’s. Other universities do not publish an M cap, but a science or engineering program’s prerequisites are all U courses anyway, so the cap is rarely the binding constraint.
ENG4U is always one of the six. Every Ontario university requires it for every direct-entry program, and Western’s nursing page shows the other pattern to watch: a required course can carry its own minimum, “Minimum 70% in each of” ENG4U, SBI4U and SCH4U, separate from the average (Western, Ontario high school). Two checks, not one: the average, and the floor under each named course.
Prerequisites are locked in, even at a low mark
This is the edge case that costs the most, because it feels unfair and it is not negotiable. If your program requires a course, that course is in the six no matter what mark it carries, and no seventh course can push it out. A 71 in MCV4U for an engineering applicant sits in the average beside the 96 in Data Management. Western describes its process as “the grades in required courses for your program, plus your highest grade 12 grades.” Required first, highest second.
The practical consequence: when you pick a second-choice program, pick one whose prerequisites are your strong courses. The same transcript produces a different top 6 for Commerce than for Life Sciences, because the forced-in courses change.
Two worked examples
ENG4U 84, MHF4U 91, MCV4U 78, MDM4U 95, BAT4M 93, BOH4M 94, HSB4U 89, SPH4U 72. The program requires ENG4U and MHF4U. Those two go in first. The four highest remaining are MDM4U 95, BOH4M 94, BAT4M 93 and HSB4U 89. Top 6: 84, 91, 95, 94, 93, 89, which averages 91.0. The 78 in Calculus and the 72 in Physics never touch the number. Student A picked their eight courses well: two spare marks to absorb a bad semester.
The program requires ENG4U, MHF4U, MCV4U, SCH4U and SPH4U. Student B has no SCH4U, so they are ineligible until they add it, and the four they do have are forced in: 84, 91, 78, 72. Only two free slots remain, filled by MDM4U 95 and BOH4M 94. Top 6: 84, 91, 78, 72, 95, 94, which averages 85.7. Same transcript, five points lower, before Waterloo’s adjustment factor or anyone’s video interview enters the picture. If you are Student B, the fix is not a seventh elective. It is the Physics mark.
Grade 11 marks: when they count and when they stop
Grade 11 marks are never part of the final admission average. Western says so in plain words: Grade 11 courses “will not be used in the calculation of your admission average.” What they do is stand in for Grade 12 marks that do not exist yet, which in Ontario means the November to February offer rounds. How much they stand in varies:
- Western reviews “a combination of Grade 11 and Grade 12 grades available at the time of each offer round” and will also “consider your overall grade 11 performance.”
- U of T makes conditional offers on “final 3U/M and interim or final 4U/M results” between mid-February and late May; if a Grade 12 prerequisite mark is missing, the Grade 11 course mark is used in its place (OUInfo, U of T).
- Queen’s can base a decision on “final Grade 11 results (with registration in appropriate Grade 12 courses), final first semester Grade 12 results and/or Grade 12 interim results.”
- McMaster may use Grade 11 in the preliminary review, but “applicants will not be refused based on Grade 11 grades.” Its rolling offers start once you present three final or six interim 4U/M marks (OUInfo, McMaster).
- uOttawa bases early offers on “the average of five 3U/M grades or a combination of 3U/M and available 4U/M final grades,” then from February to April uses the top six final 4U/M or 3U/M marks with at least two 4U/M, and in May and June the top six 4U/M only (OUInfo, uOttawa).
- Guelph uses the top six completed 4U/M where it can, otherwise “a combination of the top 6 completed or in-progress 4U/M and completed 3U/M courses” (OUInfo, Guelph). York and TMU say they may consider 3U/M results for early decisions.
Read that list as a timeline. A strong Grade 11 buys you an early offer and a quiet spring. A weak Grade 11 costs you nothing once six Grade 12 marks exist, unless a specific program (Waterloo Architecture, McMaster Midwifery) names a Grade 11 course outright.
Which marks the universities actually have, and when
Universities do not see your report card. They see whatever your school sent to OUAC by each transmission deadline, and they make offers in rounds after each one. For the 2027 entry cycle the schedule is (OUAC Guidance, 2026–2027 Schedule of Dates):
| School deadline | What is sent | What it means for you |
|---|---|---|
| 19 Nov 2026 | Every midterm or final 4U/M grade available, plus your Grade 11 finals | Early offers. Semester-one midterms carry the file. |
| 11 Feb 2027 | All available final 4U/M grades, plus current grades in full-year courses | Semester-one finals replace the midterms. The first round most programs treat as real. |
| 22 Apr 2027 | Midterm or final 4U/M grades, interim grades for full-year courses | Semester-two midterms. This is the average that drives the May offer round. |
| 8 Jul 2027 | All final 4U/M grades | Your offer’s conditions are checked against this number. |
Three things follow. A semestered student’s second-semester courses are only ever midterms in the April file, so the May offer is made on a number that will still move. A non-semestered student never has a final mark before July, so every round is interim. And a course that finishes after the July deadline is, for most purposes, a course that does not exist: McMaster says “courses completed after June 30 will not be included in the admission average calculation,” and TMU requires all admission requirements to be complete by June 30, which “will exclude the possibility of using summer school, night school, virtual school and/or distance education courses completed after this date” (OUInfo, TMU).
Repeated courses: nine universities, four different rules
Both attempts appear on what OUAC sends. Queen’s puts it directly: “Ontario universities support full disclosure of all marks achieved in all attempts at a high school course.” What each university then does with the two marks is the part students get wrong, because it is genuinely different from one to the next.
| University | Published rule for 2027 entry |
|---|---|
| Waterloo | Highest grade, all programs. “If you repeat a course and apply to any program at Waterloo for September 2027 entry, you will not be penalized” (Waterloo, Repeated courses). This is new; the old Engineering penalty is gone. |
| McMaster | Highest grade for up to two repeated courses. More than two repeats, or one course three or more times, “may be asked to provide a letter explaining the need.” |
| Western | “If you have 2 repeats, we’ll take the highest of the 2. If you have 3 or more repeats, we will take the average of your attempts” (OUInfo, Western). |
| Queen’s | Most recent grade, not highest: “all undergraduate programs will use the most recent grade achieved.” Retake a course and score lower, and the lower mark is the one Queen’s uses. |
| U of T | No formula. It “reserves the right to give preference to students whose marks are the result of a single attempt at each course.” |
| York | Highest grade, “which may not necessarily be the most recently taken course.” Schulich “reserves the right to review each situation on an individual basis” (OUInfo, York). |
| Carleton, uOttawa, Guelph | Highest grade (Guelph: highest “from a Ministry-inspected institution”) (OUInfo, Carleton). |
| TMU | Best six final marks, “which may include repeated/upgraded course marks.” |
Upgrading after you graduate is a repeat in every row of that table. So is retaking a course in summer school. The Queen’s rule is the one to memorize, because it is the only one where a retake can make your file worse, and the U of T line is the one to respect, because “single attempt” is the standard its most competitive programs can afford to apply.
Summer school, night school, online and private credits
They count, on three conditions: the school is accredited by the Ministry of Education, the mark is sent through OUAC, and it arrives before the deadline the program cares about. Western’s version: “Your courses must meet the same level of rigour as your regular day school courses and must be sent through OUAC.” Waterloo, for 2027 entry, lists day school, summer school, night school, online and private school as accepted and says outright that it “will not penalize you if you choose to take courses outside of your regular day school.” That is a change; if you read older advice about Waterloo Engineering treating private-school credits with suspicion, it is out of date.
What does still exist at Waterloo Engineering is the adjustment factor: a school-by-school correction built from how past students from your high school performed in first year relative to their admission averages. Waterloo describes it as “only a small part of the overall admissions decision,” behind academic performance, the AIF and the video interview (Waterloo Engineering FAQ). You cannot see your school’s number and you cannot change it. It is one more reason the interview is worth preparing for.
Rounding
No Ontario university publishes a rounding rule that helps you. Your school reports each mark as a whole number; the average is computed to decimals and compared to a cut-off that is also a decimal. uOttawa is the one that says it in writing: admission averages are not rounded up, and an 84.9 should not be assumed to equal an 85 (uOttawa, Ontario admission requirements). Treat that as the rule everywhere. Published cut-offs like “low 90s” are last year’s admitted range, not a promise, and Queen’s warns its minimums “vary from year to year and could be higher than what is published.”
More than six, fewer than six, and the conditions on your offer
- A seventh course only helps if it beats your sixth. It can never displace a prerequisite. Taking it for insurance is sensible; taking it hoping it will bury a required course is a misunderstanding of the rule.
- Fewer than six by July is a failed condition. Every offer is conditional on the OSSD, six 4U/M courses including the prerequisites, and a final average named in the offer letter. Guelph’s deadline for meeting all conditions is 16 July 2027; McMaster and TMU draw the line at 30 June.
- The condition is usually lower than the cut-off. The number in your offer is the floor you must hold, not the average you were admitted on. Drop below it and the offer can be withdrawn; Carleton says it will “attempt to provide an alternate offer” where possible, which is not a guarantee.
- Scholarship math is stricter. Carleton recalculates its entrance scholarship upward if your May average is higher, keeps the original if it is lower, and does not reassess on June or July marks. Other schools publish their own rules; read the scholarship page, not just the admission page.
Before you close this tab
If your average puts you in a program’s range but not comfortably, the how much a supplementary application matters guide shows which programs read the supp app as a tiebreaker and which never look past the number. If you would rather be judged on the number alone, the grades-only programs guide lists which Ontario programs admit on the top 6 and nothing else. Every supp app, AIF and video date for the cycle is in the deadlines calendar. And if UBC is on your list, forget everything above: it reads all of Grade 11 and 12, and the core vs overall average guide explains why a 94 top 6 can be a mid-80s file in Vancouver. Then put the part you can still change on a clock: AcceptMe records your interview answers, transcribes them and shows you the coach’s notes, and marks each written answer line by line.
Keep reading
- How Much Does a Supplementary Application Really Matter? How Ontario programs weigh supp apps, videos and AIFs against your top 6, and where your prep time actually pays off.
- Ontario Programs With No Supplementary Application Which Ontario university programs admit on grades alone, which need a supp app or video, and how to build a realistic application list.
- Core Average vs Overall Average: What UBC Counts Which grade 11 and grade 12 courses UBC actually uses, how core average differs from top 6, and when each one matters.