Platform/Usability (SUS)
Usability testing
Usability (SUS)

Score usability on the standard scale.

The System Usability Scale is a validated 10-item questionnaire that yields a 0–100 score — benchmarked against the industry norm, graded A–F, with sub-scale breakdown, item-level diagnosis, and score distribution.

0–100 scoreA–F letter gradePercentile vs norm (68)Usability & LearnabilityItem-level breakdownScore distribution
10
Standard items
68
Industry pass line
A–F
Letter grade
0.92
Cronbach's α

Measuring usability — sound familiar?

01Guessing whether your product is "usable enough"?
02No standard number to compare against the industry?
03Can’t tell if it’s ease-of-use or learning that hurts?
04No idea which question is dragging the score down?

The SUS turns usability into one validated, benchmarked number.

01 · SUS SCORE & BENCHMARK

One number, fully benchmarked.

Score · Grade · Percentile · Acceptability · Pass rate · Cronbach's α.

Skari computes the validated 0–100 SUS score from the 10 standard items, places it on the Sauro-Lewis percentile scale, assigns a letter grade (A–F) and Bangor acceptability label, reports the pass rate (% respondents ≥68), and checks reliability with Cronbach's α.

SUS Score & Benchmark

n=30

SUS SCORE

77.9

Grade B · Good

PERCENTILE

78.6%

vs norm (68)

PASS RATE

76.7%

respondents ≥68

ACCEPTABILITY

Acceptable

Bangor scale

RELIABILITY

0.92

Cronbach's α · good

Benchmark Position

F
D
C
B
A
0avg 68100

Sub-scales

Lewis & Sauro

Usability

77.9

Grade B

Learnability

77.9

Grade B

"Usability" is the weaker dimension at 77.9. Simplifying core flows and reducing friction may help.

Score Distribution

0avg 68100

Median 80, SD 14.9. Tight spread — a consistent experience across users.

02 · SUB-SCALES & SCORE DISTRIBUTION

Usability vs Learnability.

Lewis & Sauro sub-scales — where the weakness lies.

The Lewis & Sauro two-factor model splits the SUS into Usability (items 1–8, even-odd) and Learnability (items 4 and 10). Comparing the two scores points to the bottleneck — whether users struggle with ease-of-use or with learning. The Score Distribution chart shows how individual SUS scores spread against the 68 benchmark.

03 · ITEM-LEVEL BREAKDOWN

See which items drag the score down.

Each item scored 0–100. Lowest = biggest opportunity.

Skari scores each of the 10 SUS items on a 0–100 scale (reverse-coded items corrected automatically). The item-level chart ranks them from weakest to strongest so you know exactly which aspect of the experience to improve first. The weakest item is flagged and interpreted.

Item-level Breakdown

0–100 per item · lowest = priority

I found the system unnecessarily complex.
68.3
I think I would like to use this system frequently.
72.5
I found the various functions well integrated.
75
I would imagine most people learn quickly.
75
I needed to learn many things before use.
77.5
I thought the system was easy to use.
79.2
I found the system very cumbersome.
80.8
I felt very confident using the system.
81.7
I thought there was too much inconsistency.
90.8

Weakest item: "I found the system unnecessarily complex." (68.3) — highest priority for improvement.

Segment Analysis

Age range
18–24n=6
82.1A
25–34n=8
79.4B
35–44n=7
77.2B
45–54n=5
74C
55+n=4
68.5D

55+ segment scores near the 68 pass line — may benefit from simplified navigation.

04 · SEGMENT ANALYSIS

Does usability differ by user group?

Compare SUS scores across any survey dimension.

Select any categorical question to split respondents into segments — by age, device, experience level, or role. Skari computes a separate SUS score and grade for each group, making it easy to spot which segment has the worst experience and needs the most attention.

IN THE REPORT

Everything the SUS report delivers.

10 items in — score, grade, sub-scales, and diagnosis out.

SUS score

Validated 0–100 score from the 10 standard items.

Letter grade

A–F grade with Bangor acceptability label.

Percentile vs norm

Sauro-Lewis percentile against the 68 benchmark.

Pass rate

Share of respondents scoring at or above 68.

Sub-scales

Usability vs Learnability two-factor split.

Score distribution

How individual scores spread against the norm.

Item-level breakdown

Each item scored 0–100 to find the weakest.

Reliability check

Cronbach’s α to confirm internal consistency.

Segment comparison

SUS score and grade by any survey dimension.

Auto interpretation

Plain-language reading of the result and priorities.

Measure usability the standard way.

10 items in · SUS score, grade, percentile, sub-scales, item breakdown, and segment analysis out.

No credit card required
Industry benchmark included