The Trustpilot TrustScore is calculated on a scale from 1 to 5, but it’s not a simple average of all the reviews. It’s a Bayesian, time-weighted score, meaning the weight of the review is different depending on when it was given.
The TrustScore is an important element in any business’s profile because it signals reliability and credibility, and it gives the customer confidence to go ahead and choose their services. It is a way to measure how satisfied reviewers are with a business.
Some factors contribute to the TrustScore, such as recency, frequency, and Bayesian average. This article will show you all those factors and tell you how to utilize those factors to improve your score.
TrustScore vs. star rating vs. your review average
Many people confuse these 3 things, so let’s break them down:
- TrustScore: The Score generated from all your reviews on a scale of 1 to 5, with more weight given to newer reviews. Thus, calculating a different result from simply averaging all the reviews.
- Star rating: The star rating is simply a visualisation of the TrustScore, rounded up to the nearest half or full star. So a TrustScore of 4.39 will simply give a star rating of 4 and a half Stars.
- Your review average: This is the simple average of all the reviews you have received. It is often different from the TrustScore because they use different averaging methods.
So all 3 of these things are different in how they are calculated and what they are used for.
The 3 factors Trustpilot uses to calculate your score
According to Trustpilot’s official website, they use 3 factors to calculate the TrustScore.
Recency
The TrustScore is used to show the current state of a business. The latest customer reviews are a better representation of that than older reviews. So new reviews are given more weight in calculating the TrustScore. A 5-star rating today and a 5-star rating 2 years ago will not have the same value in the calculation. That is why smart business owners keep reviews fresh all the time.
Frequency
Since different weights are assigned to reviews based on the time they were given, a steady stream of reviews makes sure that the TrustScore is stable. Irregular reviews cause the rating to fluctuate and end up giving the business a poorer score. A good practice is to get consistent Trustpilot reviews for your business to improve TrustScore.
Bayesian average
The calculation of the TrustScore includes roughly 7 neutral ratings of 3.5 stars added in the mix to give all the companies a balanced start to their scores early on. As more reviews are given, the impact of these neutral reviews becomes less significant. If you need more reviews to reduce the impact, consult a review management professional.
The Trustpilot TrustScore formula, in plain English
Here’s a quick breakdown of the formula used to calculate the TrustScore:
The formula
“TrustScore ≈ (sum of your weighted review scores + starting cushion) ÷ (weight of your reviews + size of the cushion)”
Every business starts its profile with a cushion to help maintain a rating balance with other businesses. All businesses by default have a cushion of approximately 7 average ratings of 3.5 stars added to their number of total reviews.
With new reviews added to the total, the effects of this initial cushion are reduced, giving a more accurate score. This initial cushion is also the reason for showing hugely contrasting scores from customer ratings at a low number of total reviews.
Each review is weighted differently depending on the posting timeline. As more and more time goes by, there is a decay in the value or weight of the reviews that come into the calculation when we talk about TrustScores. Trustpilot does not disclose its exact decay values, but from independent analysis, we can say the approximate decay band is:
| Review Time | Weight (Approx.) |
|---|---|
| 0–12 months old | Full weight (approx. 100%) |
| 12–24 months old | Decreased (approx. 70%) |
| 24–36 months old | Less than half (approx. 45%) |
| 36+ months old | Minimal (approx. 30%) |
No review becomes obsolete, but with time, it loses its value.
A real example: why 50 five-star reviews can still show 4.4
Let’s look at a real example of a business that has 50 five-star reviews and 2 one-star reviews – a total of 52 reviews- but its TrustScore still shows a score of 4.4 only.
- Step 1 – The spreadsheet math: If we try to calculate the score using a simple average method, all the numbers add up to an average score of 4.85. This is the number the business owner expects to see in his profile.
- Step 2 – Add the cushion: As discussed before, Trustpilot adds approximately 7 ratings of 3.5 stars on each business that impacts their initial TrustScore. In this case, since these default ratings are lower than the business’s real customer reviews, the average review score comes down by a significant margin.
- Step 3 – The result: Due to the effects of the initial cushion, the final TrustScore of the business has dropped to 4.4 from its actual consumer review average of 4.85. This result shows the impact of low counts of consumer reviews. As more reviews start to pile up, the effects of the cushion will stop impacting the score by such a huge margin.
The more consumer reviews a business has, the more accurate TrustScore they will generate.
3 things about your score that confuse everyone
Understanding how the scoring system works is quite a difficult task, especially if someone is new to the platform. Many people have questions such as:
I’m brand new with two 5-star reviews – why is my score only 3.8?
The disparity between actual reviews and scores often alarms business owners. Without a formal understanding of the scoring system, one can feel anxiety about what they’re doing wrong. In this particular case, the business only has 2 reviews; add these 2 to the approximate 7 pre-defined rating scores of 3.5 stars, and your average score for the Trustpilot business profile drops significantly to 3.8.
Why do bad reviews drag me down more than good ones lift me up?
It might feel unfair to people that they are punished more for bad reviews than they are rewarded for good ones. It is simply a case of cushion distribution. The 7 approximate cushions are placed at a neutral 3.5 rating point.
The business can only go up by 1.5 points to reach a maximum score of 5 through reviews; on the other hand, the user can go as low as 1 point to see a point reduction of 2.5 from the pre-placed ratings. Resulting in a harsher outcome for bad reviews.
My score dropped, and I didn’t get any new bad reviews – how?
It might seem strange when you see your rating drop even with the addition of a good or neutral review. There is an explanation for this. With each added review, the entire score is recalculated, including older reviews that have entered a different decay band from last time the score was generated, thus reducing the weight of those older reviews and reducing the total score.
If you want to learn more about how you can get your score back on track, we have many helpful articles that address exactly that; you can check out Why your Trustpilot rating dropped?
How many reviews does it take to raise your score?
Let’s dig a little deeper and take a look at how the effects of adding a new review change with the increasing volume of total reviews:
| Your current review count | Effect of one new 5-star review |
|---|---|
| ~10 reviews | noticeable jump (approx. +0.07) |
| ~50 reviews | small (approx. +0.025) |
| ~200 reviews | tiny (approx. +0.007) |
| ~1,000 reviews | barely moves (approx. +0.001) |
| ~5,000 reviews | Insignificant (approx. +0.0003) |
| ~10,000 reviews | Unnoticeable (approx. +0.00015) |
| ~20,000 reviews | Negligible (approx. +0.000075) |
| ~50,000 reviews | Negligible (approx. +0.00003) |
| ~100,000 reviews | Negligible (approx. +0.000015) |
| ~500,000 reviews | Almost nonexistent (approx. +0.000003) |
Common myths about the TrustScore
There are many myths and misconceptions about TrustScores.
- Paying Trustpilot raises your score: This is a myth. Although Trustpilot offers premium services to business owners, the services are centred around inviting more people to their page, managing their profile, and in-depth analysis and breakdown of their performance.
- You can ask Trustpilot to manually bump your score: This is, again, incorrect. The TrustScore that Trustpilot generates comes from a simple formula that is entirely based on customer reviews and no intervention from Trustpilot itself.
- Once reviews get old, they stop counting: This is only partly true. We’ve discussed in this article how the value of the rating decreases as they get older, but it never becomes obsolete. So they never stop counting.
Frequently asked questions
Why is my TrustScore below my review average?
TrustScore isn’t just an average of all your total reviews. Businesses start with a cushion of neutral scores added to their rating to balance their Score. This has a significant impact early on, especially when the review count is low.
How is the star rating different from the TrustScore?
The star rating is just a visual representation of the TrustScore rounded to the nearest half or full star. While TrustScore gives us the exact value, the star rating is used to signal value and provide a visual impact on screen.
How often does the TrustScore update?
The TrustScore is updated after each review is added to the business, up until a threshold value of approximately 10,000+ reviews. After around 10,000 reviews, the score is updated about once a day.
Can my business reach a perfect 5.0?
It’s impossible to reach a perfect rating of 5.0 because Trustpilot adds seven 3.5-star ratings while calculating the rating, dragging down high-rated profiles. Mathematically, because of those extra rating scores, the highest possible rating achievable is a score of 4.99.
What is a good Trustpilot score?
According to their website, Trustpilot rates scores of 4.3 and above as Excellent. These are businesses with 4 and a half or 5-star ratings. Scores falling in the range of 3.8 to 4.2 are classified as Great scores, typically having 4 stars.
