Six subjects, three bonus points, and the failing conditions that catch people who thought they had passed.
Everyone knows the IB Diploma is marked out of 45. Very few people can explain where the 45 comes from.
That matters more than it sounds. The IB is not one score with one threshold. It is two separate calculations added together, sitting on top of a set of rules that can fail a strong candidate outright.
Students work out their total wrong all the time. Usually they are too optimistic, and they find out in July.
Here is the whole system, in the order it actually gets calculated.
Where the first 42 points come from
Every IB Diploma student takes six subjects. Each one is graded from 1 to 7, where 7 is the top. Six subjects at a maximum of 7 gives you 42.
The diploma is two calculations, not one. The three points at the bottom follow different rules entirely.
Three of those subjects are taken at Higher Level and three at Standard Level, one from each of six subject groups. Some students take four at Higher Level and two at Standard. The full structure is set out by the IB itself.
Here is the part that surprises people. A 7 at Standard Level is worth exactly the same as a 7 at Higher Level. Both are worth 7 points.
Higher Level is harder, covers more content, and takes far more teaching hours. It is not worth more points. Universities notice the difference. The 45 point scale does not.
That has a consequence most students miss. When you decide where your hours go, think in points, not in difficulty.
A subject already sitting at 7 has nothing left to win. Where one weak subject is dragging the total down, targeted IB tutoring support in that single subject moves the number faster than spreading revision evenly across all six.
Most students do the opposite. They revise everything a little, including the subjects where there is nothing left to gain.
Where the last three points come from
The final three points come from Theory of Knowledge and the Extended Essay. Each is graded from A to E, not from 1 to 7.
Those two letters are then combined, and this is where nearly everyone gets it wrong. The points are not added. They are looked up.
The IB uses a fixed matrix. Find your TOK grade down the left, your essay grade across the top, and read off the number where the two meet.
| EE grade A | EE grade B | EE grade C | EE grade D | EE grade E | |
| TOK grade A | 3 | 3 | 2 | 2 | Fails |
| TOK grade B | 3 | 2 | 2 | 1 | Fails |
| TOK grade C | 2 | 2 | 1 | 0 | Fails |
| TOK grade D | 2 | 1 | 0 | 0 | Fails |
| TOK grade E | Fails | Fails | Fails | Fails | Fails |
Read the grid carefully and two things jump out.
An A in the Extended Essay does not guarantee three points. Pair it with a D in TOK and it is worth two. The weaker of the two grades does most of the work.
And an E in either one fails the entire diploma. Not the essay. The diploma. A student sitting on 41 points from their subjects walks away with nothing.
Which point is cheapest to buy
Once the matrix is clear, a useful question appears. A point is a point, wherever it comes from. So the question is not which piece of work matters most. It is which point costs the least effort.
Moving a subject from a 5 to a 6 is worth one point. Moving TOK from a C to a B, where the essay is already at B or above, is worth one point too.
The second is often a fraction of the work. TOK is a single assessment. A subject grade is two years of content and three exam papers.
This cuts both ways. If TOK and the essay are already at A and B, there are no bonus points left to win, and the only route up is through the subjects.
Work out where your points are missing before you decide where your hours go. The calculation takes ten minutes and it will change your timetable.
Twenty four points is not the same as a pass
This is the most misunderstood rule in the whole diploma. Twenty four is the minimum score. It is not the definition of a pass.
A candidate can clear 24 comfortably and still be refused the diploma. The IB applies a list of separate conditions, and failing any one of them ends it.
The table below covers each condition and what it means once you are actually sitting the exams.
| The condition | What it means in practice |
|---|---|
| CAS is not completed | Creativity, Activity, Service carries no points at all. Skip it and the diploma does not come, whatever the score says. |
| Total is below 24 points | The headline threshold. It is necessary, and on its own it is not sufficient. |
| An N is recorded | An N means no grade was issued, usually a missing piece of work. One N in TOK, the essay or a subject ends it. |
| An E in TOK or the essay | A single E in either one fails the whole diploma, even from a candidate scoring in the forties. |
| A grade 1 in any subject | One subject at 1 fails the diploma outright, at either level. |
| Three or more grade 2s | Counted across both levels together. |
| Four or more grades of 3 or below | Also counted across both levels together. |
| Fewer than 12 points at Higher Level | Where four HL subjects were taken, the three highest grades are the ones counted. |
| Fewer than 9 points at Standard Level | Where only two SL subjects were taken, the minimum is 5 points. |
Look at the pattern in that list. Most of the conditions are about your floor, not your ceiling.
The diploma does not care very much how high your best subject went. It cares a great deal about how low your worst one fell.
This is the opposite of how most students revise. A 7 in your strongest subject cannot rescue a 1 in your weakest, because the 1 fails you regardless of the total.
What counts as a good score
Because the scale runs to 45, students often read anything below 40 as a failure. That is not how the numbers sit in practice.
The world average has stayed close to 30 for years, although it moves from session to session. A score in the mid thirties is a strong result almost anywhere.
Scores of 43 and above are rare enough to make school newsletters. A perfect 45 is rarer still. Very few university offers ever ask for one.
Check the current session statistics before setting a target. Anchoring on 45 usually produces a plan that is neither realistic nor necessary.
What universities actually look at
The total is the headline. It is rarely the whole offer.
Most competitive university offers name two things. A total, and specific grades in named Higher Level subjects. An offer might read 38 points with 766 at Higher Level.
That second half is the part students underestimate. Meeting the total and missing one HL grade can still lose the place.
It also means the two scores are not interchangeable. Forty points built on strong Higher Level grades is a different application from forty points built on Standard Level results and three bonus points.
Check the exact wording of any offer before planning revision around it. The HL requirement often decides where the effort should go.
Four calculations people get wrong
These come up constantly, and each one produces a total that is too high.
- Adding TOK and the Extended Essay separately. They are combined through the matrix, and the maximum from both together is three.
- Assuming Higher Level scores more. A 7 is 7 at either level.
- Treating 24 as an automatic pass. The conditions apply on top of the total, and any one of them overrides it.
- Averaging predicted grades. Predictions are a teacher’s estimate, not a result, and the gap between the two runs in both directions.
The honest version of the calculation is short. Add your six subject grades. Look up the matrix. Then read the conditions and check that none of them apply to you.
If the number that comes out is lower than you expected, you now know that in November rather than July. That is the entire point of doing it early.
