--- title: "Star rating calculator — average & reviews needed — Testymo" description: "Work out your exact average star rating from per-star review counts, then flip it: how many more 5-star reviews you need to reach the rating you want. Free, in your browser." url: https://testymo.com/free/star-rating-calculator --- [Free tools](https://testymo.com/free) ★ Star rating calculator # Star rating calculator Type in how many reviews you have at each star and get the exact average — then turn it around and see how many five-star reviews stand between you and the number you want on the door. - **What it costs** — Nothing. No account, no email, no watermark, no limit on how often you use it. - **Where your text goes** — Nowhere. The whole tool runs in your browser — nothing you type is sent, stored, or seen by us. The page-view measurement this site carries counts the visit, never the text. Your reviews, by star ★★★★★ 5-star reviews ★★★★ 4-star reviews ★★★ 3-star reviews ★★ 2-star reviews ★ 1-star reviews Your average across reviews ## 01 How the average is worked out A star rating is a weighted mean: each star level multiplied by how many reviews sit on it, summed, divided by the total. Thirty-two five-star reviews and two one-star reviews are not “mostly five stars” — they are exactly `(32×5 + 2×1) ÷ 34`, and the second decimal is where movement shows up first. Review platforms usually display one rounded decimal, so two ratings that read the same on the surface can be a dozen reviews apart underneath. This calculator keeps two decimals so you can see the number actually move. ## 02 Why the reverse number is always bigger than you hope A new five-star review can move an average of `n` reviews by at most `(5 − average) ÷ (n + 1)` — and that shrinks with every review you already have. At 38 reviews and a 4.2 average, one more five-star review moves you by about 0.02. That is the honest arithmetic behind the tool’s answer: averages get heavier as they grow, so the earlier you start collecting, the cheaper every tenth of a star is. The same weight works for you once you are ahead: a rating built on hundreds of reviews barely flinches at one bad week. The number this tool gives you is not a vanity target — it is ballast. ## 03 What to do with the number “We need 23 more five-star reviews” is a collection problem, and collection is mostly about asking — the right person, at the right moment, with a form short enough to finish. [How to ask for a testimonial](https://testymo.com/blog/how-to-ask-for-a-testimonial) covers the moment and the wording, and if you are starting from zero, [there is a playbook for that too](https://testymo.com/blog/get-testimonials-with-no-clients). One caution while you chase the number: a star average persuades most when there are words next to it. A rating with no readable quotes underneath asks a visitor to trust arithmetic alone — [why real testimonials look fake](https://testymo.com/blog/testimonials-look-fake) is about what makes proof believable, and specificity beats polish every time. ## 04 Questions this page gets - **Will this match what my review platform shows?** — The arithmetic is the same weighted mean every platform uses; the difference is display. Most platforms round to one decimal and some round in steps, so their badge can sit still while your underlying average moves. Enter the counts from any platform and you get the unrounded number. - **Can an average get back to a straight 5.0?** — Only if every single review is five stars. Once anything lower exists, new five-star reviews push the average toward 5.0 without ever reaching it — which is why the tool tells you plainly when a target is out of range instead of printing an enormous number. - **Does the calculator handle half-star reviews?** — It works in whole-star counts, which is how nearly all review platforms collect. If yours allows halves, put each half-star review in the nearest whole bucket and read the result as an approximation. More free tools - [Testimonial slider & HTML generator I need a testimonial slider or section, as code I can paste.](https://testymo.com/free/testimonial-html-generator) - [Testimonial request generator How do I actually word the ask?](https://testymo.com/free/testimonial-request-generator) - [Testimonial question picker What should I actually ask my customers?](https://testymo.com/free/testimonial-question-picker) - [Testimonial image generator How do I turn this quote into something postable?](https://testymo.com/free/testimonial-image-generator) - [Google review link generator How do I send someone straight to my Google review box?](https://testymo.com/free/google-review-link-generator) The part no tool does A tool can shape what you already have. Testymo is for getting it: a testimonial form people actually finish, your approval on every word before it goes public, and the permission recorded alongside it. Free to start — no card, no view meters. [Collect your first testimonial →](https://testymo.com/app?utm_source=free&utm_campaign=star-rating-calculator)