Understanding IB grade boundaries gives you a strategic advantage most st
IB Grade Boundaries Explained: How Your Final Score Is Actually Calculated
Understanding IB grade boundaries gives you a strategic advantage most students don't have. Here's how the system really works.
What Are Grade Boundaries?
Grade boundaries are the minimum raw marks needed for each grade (1-7), set after each exam session based on paper difficulty and global student performance.
Typical Chemistry HL boundaries: 7 = 76%, 6 = 64%, 5 = 52%, 4 = 38%. But these shift every year.
How Your Score Is Calculated
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Raw marks from each paper
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Weighting applied (Paper 1: 20%, Paper 2: 40%, etc.)
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Grade boundaries applied to weighted total
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Final grade (1-7) assigned
Strategic Takeaways
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You don't need 90% for a 7 — boundaries typically fall at 70-80%
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Every mark counts equally — easy marks are worth the same as hard ones
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IA is your secret weapon — high IA scores give you exam buffers
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Know your gap — if you need 6 more marks for a 6, that's specific and fixable
Common Misconceptions
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The IB doesn't "curve" — boundaries are based on difficulty, not rank
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Boundaries shift 5-10 marks between sessions
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Different subjects require different percentages for the same grade
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IB grade calculation FAQs
Is an IB final subject grade the average of separate paper grades?
No. The IB aggregates marks from the assessment components after any required scaling or weighting. The resulting overall subject mark is then converted to a grade from 1 to 7 using the relevant boundaries.
Does every IB subject use the same paper and IA weightings?
No. Component structures and weightings depend on the subject, level and applicable course guide. Use the current assessment outline for the exact course rather than a generic example from another subject.
Can a previous IB grade boundary predict my final grade?
A historical boundary can provide context for that particular session, but it is not a guaranteed future cutoff or a complete predicted-grade method. Teachers predict grades from evidence of student work and knowledge of IB standards.
Is the 1–7 subject grade the same as the 45-point diploma score?
No. Each DP course receives a grade from 1 to 7. The six subject grades are combined, and TOK and the Extended Essay can contribute up to three additional core points, producing a maximum diploma score of 45 subject to the diploma requirements.
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