The score is deliberately simple, so that anyone can check it. It is the percentage of the WCAG 2.1 AA success criteria that apply to your pages, and that your pages pass.
Step by step
- Start with all 49 success criteria in WCAG 2.1 levels A and AA.
- Remove the ones that do not apply. If your pages have no video, the criteria about captions and audio description are marked not applicable by the specialist and left out.
- Mark each remaining criterion pass or fail. A criterion fails if an automated test found a failure for it on any scanned page, or if the specialist found one during the review.
- Divide the passes by the applicable criteria and round to the nearest whole number.
A worked example
Your site has no video or audio, so the specialist marks 4 criteria not applicable. That leaves 45 that apply. Of those, 6 fail.
| Applicable criteria | 49 minus 4 = 45 |
| Passing criteria | 45 minus 6 = 39 |
| Score | 39 divided by 45 = 86.7%, rounded to 87 |
| Risk band | Needs Attention |
Automated failures always count
If an automated test found a real failure for a criterion, that criterion fails. The specialist cannot mark it as a pass. The review adds judgement on top of the automated results; it does not overrule an objective failure.
What this means in practice
- Each failing criterion costs the same. Failing contrast costs the same as failing page titles. See What moves your score, and what does not.
- A criterion fails once, however many times it fails. One unlabelled field and fifty unlabelled fields both fail the criterion once.
- Each criterion is worth roughly two points. With 45 applicable criteria, each one is worth just over 2.
Why it is done this way
This is how conformance to WCAG is actually judged: requirement by requirement, pass or fail. It also means your score maps directly onto the list of criteria in your expert audit, so every point lost can be traced to a named requirement.