Many product teams have never heard of the System Usability Scale (SUS), so it’s understandable that someone getting their first survey results might see a score of 71 and think, “..is that good?”.

The short answer is: it’s above average, but it’s unlikely people will be evangelising your product.

Here’s what your score actually means — and how you can use it to improve your design strategy.

What the System Usability Scale is

The System Usability Scale (SUS) is a 10-question survey that measures how usable your product feels to the people who actually use it. It was developed in 1986 by John Brooke at Digital Equipment Corporation in the UK, and it has since become the most widely used usability measurement tool in the world, with over 20,000 academic citations and decades of real-world application across software, hardware, websites, and apps.

The survey asks users to rate ten statements on a scale of 1 to 5 — things like “I found this system unnecessarily complex” and “I thought the system was easy to use.” Their responses are combined into a single score between 0 and 100.

That score is not a percentage. A 70 doesn’t mean your product is 70% usable. It means something more specific — and more useful.

The benchmark numbers you need to know

Based on analysis of over 500 usability studies, researchers have established clear thresholds for interpreting SUS scores.

Below 51 — There are serious usability problems. Users are likely struggling with basic tasks, and some are probably abandoning the product entirely because of friction. This needs immediate attention.

51–67 — Below average. Users are getting by, but the experience is effortful. Retention and word-of-mouth will suffer.

68 — The average SUS score across all products tested. If you’re at 68, you’re not failing, but you’re not standing out either.

68–80 — Above average. Users generally find your product workable, though there’s meaningful room to improve.

Above 80 — This is where things get interesting. Research shows that products scoring above 80 are significantly more likely to be recommended by users. You’ve crossed from “acceptable” into “genuinely good.”

Above 90 — Exceptional. Reserved for products users find delightfully easy to use.

Why a single score is more useful than you’d think

The common objection to SUS is that it doesn’t tell you what’s wrong — just whether something is. That’s true, and it’s intentional. SUS is not a diagnostic tool. It won’t tell you which button is in the wrong place.

What it does instead is give you a consistent, comparable baseline.

That matters for three reasons.

1. It removes opinion from the conversation. When two people disagree about whether a redesign improved the experience, a SUS score before and after doesn’t care who’s more senior. The number says what it says.

2. It lets you track progress over time. A score of 71 today is just a number. A score that moves from 63 to 71 across three releases is a story about a team that’s improving deliberately.

3. It gives you something to benchmark against. The average is 68. Your industry peers are probably clustered around there too. Knowing you’re at 79 — or 54 — tells you where you sit relative to the landscape, not just whether your users clicked the right button in your last usability test.

When to measure

SUS works best when it’s repeated, not one-off. The most useful pattern is to send the survey at consistent intervals — after major releases, after significant UI changes, or on a quarterly cadence — so you build a trend line rather than a snapshot.

A single score tells you where you are. A series of scores tells you whether what you’re doing is working.

The survey itself takes users less than two minutes to complete. It’s ten questions. There’s no open-ended feedback to wrangle, no session recordings to watch, no qualitative data to code. You get a number. You track it. You know.

What to do with a low score

If your score comes back below 68, resist the urge to immediately redesign. SUS is telling you something is wrong, but not what. The right next step is to pair the score with qualitative methods — user interviews, session replays, usability testing — to identify where the friction is coming from.

The score tells you to look. The qualitative research tells you where.

If your score is above 68 but below 80, the question becomes: which interactions are pulling the average down? SUS doesn’t answer this directly, but it motivates the question in a way that gut feel never quite manages.

The bottom line

A good SUS score is one that’s improving.

A score of 80 that never moves is less interesting than a score of 62 that’s been climbing for six months, because the climbing score tells you something about how your team works — that you’re measuring, responding, and getting better.

Start with a baseline. Run the survey. Get your number. Then give yourself something to beat.