IB Diploma Score to Percentage Calculator (Approximate)

How to Use the IB Diploma Score to Percentage Calculator

1. Enter your IB Diploma total score in the box above, or click the swap icon (⇄) first if you want to go the other way (percentage → IB Diploma total score).
2. Click Convert to see your approximate percentage instantly.
3. Read the note above the calculator — it tells you whether the formula used is the university's official rule or a clearly labeled approximation.
4. Nothing you type is uploaded anywhere. The formula runs as plain JavaScript in your browser tab, and the page works the same with your network disconnected.

IB Diploma Score to Percentage — the Approximation Used Here

The International Baccalaureate (IB) Diploma Programme scores students from 1–7 across six subjects (36 points maximum) plus up to 3 bonus points from Theory of Knowledge and the Extended Essay, for a total out of 45 points. The IB itself does not publish an official percentage conversion, because the 1–7 subject scale is criterion-referenced (describing what a student can demonstrably do) rather than a direct marks average — the same 6 in Higher Level Chemistry and Higher Level History reflects very different underlying assessment criteria, not necessarily "60% of the marks available."

For a simple reference figure, this tool uses direct proportional scaling:

Approximate Percentage = (Total Score ÷ 45) × 100

This treats the 45-point maximum as equivalent to 100%, which is the same logic behind many informal "IB score to percentage" comparisons — but it is not how the Association of Indian Universities (AIU) or most credential evaluators calculate an official equivalence, which use a per-subject grade-band averaging method instead.

Worked Example

A student with an IB Diploma total score of 38 converts to an approximate:

Percentage ≈ (38 ÷ 45) × 100 = 84.44%

A total score of 32 gives an approximate 71.1%, and the maximum score of 45 gives exactly 100%. For comparison, the AIU's official method — averaging the midpoint of each subject's percentage-range equivalent (where, for example, a subject grade of 7 maps to roughly 96–100% and a 6 maps to roughly 83–95%) — can produce a noticeably different figure from this simple proportional estimate, especially for students with an uneven grade spread across subjects.

Who Needs This Calculator

This calculator is for IB Diploma students and their parents who want a quick, informal percentage estimate for personal reference, a preliminary comparison against non-IB peers, or a rough figure before requesting an official AIU equivalence certificate — which is what's actually required for admission to most Indian universities.

Official Formula vs. Approximation

This is explicitly an approximation, not an IB-published or AIU-published figure. The IB Organisation deliberately does not convert Diploma scores to a percentage, since its criterion-referenced grading isn't designed to map linearly onto a marks-based scale. For Indian university admissions specifically, the Association of Indian Universities (AIU) has recognized the IB Diploma as equivalent to Class 12 (10+2) since 1983, and issues its own equivalence certificate using a per-subject grade-band averaging method that differs from — and is more authoritative than — this tool's simple proportional estimate.

How IB Scoring Differs from a Marks-Based Percentage

Each of the IB Diploma's six subjects is graded 1 (lowest) to 7 (highest) against published subject-specific criteria, not against a raw marks total — two students can score a 6 in the same subject through different combinations of internal assessment, coursework, and exam performance, as long as both meet the same criteria. The 3 bonus points from Theory of Knowledge and the Extended Essay are added on top, capping the total Diploma score at 45. This criterion-referenced design is precisely why the IB itself avoids publishing a single percentage-equivalence formula.

Common Mistakes When Converting IB Diploma score

• Treating this tool's proportional estimate as an IB-published or AIU-published official figure
• Submitting this calculator's result instead of an AIU equivalence certificate on an Indian university admission form
• Assuming a score of 45 out of 45 is directly comparable to "100% marks" on a board exam — the two scales measure different things
• Using this proportional method for UK UCAS tariff conversion, which uses an entirely separate points table, not a percentage
• Ignoring that the AIU's grade-band method can differ meaningfully from this simple (score ÷ 45) × 100 estimate, especially for uneven subject performance

Frequently Asked Questions

Is this the official IB Diploma score formula? No — the IB does not publish an official percentage equivalent for the Diploma's total score. This tool's (score ÷ 45) × 100 estimate is a simple proportional reference; for Indian university admissions, request an official AIU equivalence certificate instead.

How does the AIU calculate the official percentage equivalence? The AIU generally takes the midpoint of the percentage range associated with each subject's IB grade (for example, a grade 7 maps to roughly 96–100%) and averages those midpoints across your subjects — a different method from this tool's simple proportional total-score scaling.

Do UK universities use a percentage for IB scores? No — UK universities and UCAS use a separate points-tariff system (roughly 1 IB point ≈ 7.89 UCAS points) rather than a percentage, so this calculator's output isn't the figure to use for UK applications.

Is my grade data uploaded anywhere? No. The conversion runs entirely as JavaScript inside your browser tab — no CGPA, percentage, or personal information is ever sent to a server, logged, or stored.

Is this tool free to use? Yes. It's completely free, with no login, no watermark, and no usage limit.