Review Rating Confidence Calculator

4.8 stars from twelve reviews is worth 3.75 as evidence. 4.5 stars from four hundred is worth 4.36. The listing with the lower average is the better rated one, and the shop front shows you the opposite.

That is not a trick and it is not new. It is why serious marketplaces have ranked on something like this figure for years rather than on the average, and why a brand new listing at five stars does not outrank an established one at four and a half.

This page does that arithmetic on any two ratings you can see: yours and a rival’s, or two of your own listings. It gives each a floor — the bottom of its range — and tells you which is genuinely better rated, and whether that answer disagrees with the averages.

The review count is the first box on the page, on purpose. It is the half of a rating nobody looks at, and it is the half that decides how much of the average is worth believing.

The table shows the same average at every review count from five to a thousand, so you can see exactly what the count is doing rather than take the answer on trust. It also works out how many reviews it would take to bring the floor within whatever distance of the average you would settle for.

It cannot see whether reviews are real, whether they were solicited, or whether they are about the product or about the courier. It counts what you type. That is worth remembering about your own numbers, and worth remembering twice about the ones you are comparing yourself against.

Save as many versions as you like and put any two side by side, figure against figure, with the better one on each line marked and the difference in its own column. That screen is the one that decides things, and it is the part a free calculator cannot do at all. Two of your own listings side by side is the comparison most people never make.

One HTML file. No account, no subscription, no internet needed. Opens on Windows, Mac and Android; the readme explains the extra step on iPhone and iPad, where Apple blocks JavaScript in downloaded files and every tool of this kind is affected.

Everything lives in your browser on your device. Nothing is uploaded, which is why it works offline and why nobody else can see your figures — and it also means clearing your browsing data deletes it. The tool does not pretend otherwise: the header shows how long since your last export at all times, turns amber after three days and red after seven, and export is one click that produces a plain file you keep.