Difficulty levels are derived from approximate Lexile ranges and adjusted to follow Zinc editorial standards surrounding text complexity, target audience, and age-appropriateness.

Zinc's Level Placement determines a student's independent reading level. After taking the Level Placement and receiving a score, a student's "Articles" home screen will show articles at the level of their reading Level Placement result. Students should start their reading journey on Zinc at that level and also feel free to read texts of interest above and below that level.

The recommended Zinc level represents a student's independent reading level. Texts at that level should be accessible to the student while also engaging and appropriately challenging the student. The Zinc levels correspond to standard Lexile and grade-level reading targets.