configured.

If you're not using Docker Scout, the health scores show the compliance of your
images with the default policies, a set of supply chain rules recommended by
Docker as foundational standards for images. You can enable Docker Scout for
your organization and edit the policy configurations to get a more relevant
health score based on your specific policies.

### Scoring process

Each policy is assigned a points value based on its
[type](/manuals/scout/policy/_index.md#policy-types). If the image is compliant
with a policy, it is awarded the points value for that policy type. The health
score of an image is calculated based on the percentage of points achieved
relative to the total possible points.

1. Policy compliance is evaluated for the image.
2. Points are awarded based on compliance with policies.
3. The points achieved percentage is calculated:

   ```text
   Percentage = (Points / Total) * 100
   ```

4. The final score is assigned based on the percentage of points achieved, as
   shown in the following table:

   | Points percentage (awarded out of total) | Score |
   | ---------------------------------------- | ----- |
   | More than 90%                            | A     |
   | 71% to 90%                               | B     |
   | 51% to 70%                               | C     |
   | 31% to 50%                               | D     |
   | 11% to 30%                               | E     |
   | Less than 10%                            | F     |

### N/A scores

Images can also be assigned an `N/A` score, which can happen when:

- The image is larger than 4GB (compressed size).
- The image architecture is not `linux/amd64` or `linux/arm64`.
- The image is too old and does not have fresh data for evaluation.

If you see an `N/A` score, consider the following:

- If the image is too large, try reducing the size of the image.
- If the image has an unsupported architecture, rebuild the image for a
  supported architecture.
- If the image is too old, push a new tag to trigger a fresh evaluation.

### Policy weights

Different policy types carry varying weights, which impact the score assigned
to an image during evaluation, as shown in the following table.

| Policy type                                                                                  | Points |
| -------------------------------------------------------------------------------------------- | ------ |
| [Severity-Based Vulnerability](/manuals/scout/policy/_index.md#severity-based-vulnerability) | 20     |