What 'Best 6' actually means. Your Best 6 is your top six Grade 12 university (U) or university/college (M) level courses, averaged together. Different programs use different compression — about half of programs use just your top six regardless of subject, while others (notably engineering and some sciences) require specific prerequite courses to be included in that six. Why it's good news for you. Because it's your top six, your average is defined by your strengths. A weaker seventh course won't drag you down. That's the entire reason a strong student with one rough subject can still hit a high admission average — and it's why the Grade Tracker projects from your top six, not your overall course load. Which courses count. To be eligible, a course must be a Grade 12 U or M level course. Grade 11 courses don't count toward your final admission average. That's a common misunderstanding — students worry about Grade 11 marks, but for many programs it's the Grade 12 courses (plus, during application season, the in-progress Grade 12 marks and sometimes final Grade 11 courses for early offers) that feed the calculation. Calculating it yourself. Take your six highest Grade 12 U/M course marks, add them up, and divide by six. The Grade Tracker here does this automatically, including a projection of what your Grade 12 average will be based on current course grades. It also runs the 'What-If' calculator so you can see how a higher mark in one course would move your overall average. Planning around it. Since it's your best six, choose courses where you can genuinely excel. It's often smarter to take seven strong courses and let the weakest fall off than to overload with eight or nine and risk your average. Universities also see which prerequite courses make up your six — for competitive programs, excelling in the required courses is what separates top applicants.