Table 2.

Interpretation of the System Usability Scale Scores³⁸

Score	Percentile	Grade
84.1–100	96–100	A+
80.8–84.0	90–95	A
78.9–80.7	85–89	A−
77.2–78.8	80–84	B+
74.1–77.1	70–79	B
72.6–74.0	65–69	B−
71.1–72.5	60–64	C+
65.0–71.0	41–59	C
62.7–64.9	35–40	C−
51.7–62.6	15–34	D
25.1–51.6	2–14	F
0–25	0–1.9	F