Home › How We Calculate the Trust Rating

How We Calculate the Trust Rating

Every listing on this site shows a Trust Rating out of 5. Here is exactly how it's calculated, in plain English, so you can decide how much weight to give it.

The Formula

The Trust Rating is a weighted average of three things we actually hold data on for each listing:

• License status (45% of the score). A listing with a confirmed, verified license scores highest. A listing where our license check turned up nothing, or where the status is simply unverified, scores lower. This is the largest single factor -- see our license verification audit for how that check actually works and how often it finds a match, state by state.
• Rating and review volume (35% of the score). We use the business's Google rating, but we don't take it at face value. A rating from 2 reviews and a rating from 150 reviews carry very different amounts of information, so we statistically shrink small-sample ratings toward the average rating across every listing on this site, currently 4.71 out of 5. In practice this means 2 five-star reviews will not outscore 150 reviews averaging 4.7; the larger, more reliable sample wins. This method is called Bayesian shrinkage, and we treat every listing as if it started with 10 reviews at the site average before its real reviews are added in.
• Listing completeness (20% of the score). Whether we have a rating, a review count, a written description, map coordinates, and at least one confirmed service for the business. A listing we know more about scores higher on this component than one where most fields are blank.

Those three components are combined into a single weighted score and shown out of 5, rounded to one decimal place.

What the Score Means

A higher Trust Rating means: the license status is more favorable, the rating is both high and backed by a meaningful number of reviews, and we hold more verifiable information about the business. It's a summary of the data we have, not a judgment call by a person.

What the Score Is NOT

• It is not an inspection. Nobody from this site has visited the business, watched them work, or checked their equipment.
• It is not a background check or a credential audit beyond the automated license-status lookup described above.
• It is not an endorsement or a guarantee. A high score does not mean we recommend this specific business over another; it means the underlying data looks more favorable by this formula.
• It is not adjustable by the business or by us on a case-by-case basis. The score is recomputed only when the underlying data changes, for example after a fresh license check or a new review count. Nobody hand-edits an individual score.

Check a contractor's license record and ask for references before you hire. See our hiring guide for the full list.