An IB score does not have one official US GPA equivalent. The IB explicitly declines to endorse a US conversion table and recommends reporting grades on its original 1–7 scale. Our IB calculator shows two separate results: your entered point total and an average using this site’s illustrative subject mapping.
That distinction matters if you are filling out an application. The illustration can help you check arithmetic, but it does not create a GPA you should report as an official result.
The point total and the GPA illustration use different inputs
The IB total adds six subject grades and any TOK/EE core points. Subject grades run from 1 to 7, giving up to 42 subject points; the core can add up to 3, for a maximum of 45. The IB’s passing criteria also require conditions beyond the total, including CAS completion and subject requirements. This calculator does not assess those conditions.
The GPA illustration maps each subject grade through the table below and averages the six values. Core points do not enter that calculation. HL and SL subjects receive equal weight here, and there is no course-credit weighting.
| IB subject score | Illustrative letter | Points used by this calculator |
|---|---|---|
| 7 | A | 4.0 |
| 6 | A- | 3.7 |
| 5 | B | 3.0 |
| 4 | C+ | 2.3 |
| 3 | C- | 1.7 |
| 2 | D | 1.0 |
| 1 | F | 0.0 |
These letters and points describe the site’s chosen mapping. They are not IB-endorsed equivalences.
Check a six-subject example
Suppose the entered grades are 7, 6, 6, 5, 5, 4, with 2 core points.
- Subject total:
7 + 6 + 6 + 5 + 5 + 4 = 33. - IB total:
33 + 2 = 35, displayed as 35 / 45. - Mapped points:
4.0 + 3.7 + 3.7 + 3.0 + 3.0 + 2.3 = 19.7. - Illustrative GPA:
19.7 ÷ 6 ≈ 3.28.
Changing the core points from 2 to 3 raises the IB total to 36. The illustration stays at 3.28 because the six subject grades have not changed.
Why a total alone cannot reproduce this average
Even two sets with the same subject total can produce different mapped averages:
| Subject grades | Subject total | Illustrative GPA |
|---|---|---|
| 6, 6, 6, 6, 6, 6 | 36 | 3.70 |
| 7, 7, 7, 5, 5, 5 | 36 | 3.50 |
For the second set, three mapped 4.0s and three mapped 3.0s add to 21; dividing by six gives 3.50. The table does not increase by an equal amount at every step, so the total of the original grades is insufficient to recover the mapped average. You need the individual scores.
Entering and checking your results
Enter all six subject scores as whole numbers from 1 through 7. Core points must be a whole number from 0 through 3; leaving that field blank makes the calculator use zero. A blank or invalid subject keeps both results hidden rather than silently averaging an incomplete record.
The displayed GPA is rounded to two decimal places. A valid score of 1 contributes zero under this mapping; it is not treated as missing. All six scores at 1 therefore show 0.00, while an unfinished form shows a dash.
What to use for an application
Read the destination’s instructions before converting anything. For example, Stanford’s undergraduate international-applicant guidance says applicants do not need to convert their marks into an American GPA. That is a named institution’s policy, not a rule for every application.
Keep your original subject grades, core points, and school grading information available. If an application requires a conversion, use its stated procedure or ask its admissions office how to complete the field. The calculator’s illustrative number is not a substitute for that instruction.
