How many 5 star reviews do you need to improve your Google rating?

TLDR:

• Almost all Google review calculators online will give you wrong values because Google rounds ratings up from .50 and down from .49.
• While the number of 5-star reviews required can be motivating, it makes more sense to look at your real-world average over the past 30 days.
• If your 30-day average rating is higher than your overall rating, you're improving. If not, your rating is effectively decreasing.
• We built a free google review calculator, that actually works – unlike the vast majority of those you'll find online.

The problem

Let's take this Tapas restaurant in Sunny Provence as an example

At the time of writing, they have 145 reviews, and Google shows a rating of 4.9.

All calculators I've tried will tell you you need 136 5 star reviews to get to a 5.0 rating.

Here's two example

Which basically means 2X the current number, with 5 star reviews only.

Which essentially tells the business owner, don't bother.

Now we can debate whether having a rating of 5.0 is better or worse than 4.9, and there's certainly a lot more to deciding whether this should be a priority or not.

But in reality, that tapas restaurant has an average rating of 4.938.

Which means getting just 35 5-star reviews would get them to a 5.0 rating. Not 135. Just 35.

That's more than 3 times less that what other calculators returned.

That's how wrong those calculators are.

The maths

• Rc: current average rating (e.g., 4.47)
• C: current review count (e.g., 200)
• R₃₀d: expected average rating of new reviews (e.g., 5)
• Rt: target rating you want to display (e.g., 4.8)

To display a rating of Rt, you need enough reviews for your "real" average to reach at least (Rt - 0.05) because Google rounds up at .50.

• n: number of new reviews needed at average rating R₃₀d to reach the target display rating Rt

Why you shouldn't count on 5 star reviews only

Getting 5 star-reviews only isn't realistic.

Especially if you haven't been getting 5 star-reviews only so far.

If you actually want to improve, and have actionable information, I recommend you look at your mobile 30 day average rating.

The mobile 30 day average is simply the average of the ratings of the reviews you collected over the past 30 days.

Compare that value with your overall rating.

• If your 30 day average is higher than your overall rating, you're improving.
• If your 30 day average is lower than your overall rating, your rating is effectively decreasing.

A Google Review Calculator that actually works

We built a free google review calculator, that actually works.

Start by searching any google location on our search bar (powered by Google). If you're having trouble finding a location, check the location's exact name – you can also try to input its exact address – or copy & paste a direct link to the location.

Select the right location in the dropdown.

Let it load for a minute – we have to pull all your reviews from Google to get you accurate numbers so it can take up to 60 seconds.

Bingo! You're on the result page.

In this example, if everything continues the exact same way, our Kebab joint will see its rating increase to 3.9 in the next 3 days.

Now for the most interesting part.

If you scroll down a bit, you'll get a simple screen with 2 outputs, and 3 inputs:

Outputs

• The number of new reviews required to get to your target rating (first input)
• The number of days required to gather that many reviews (second input)

Inputs

• The Target Rating: By default, current rating + 0.1 (next rating). You can play with this and increase it to your actual objective. Or on the contrary, use it to define an ambitious, but obtainable target.
• New reviews per month: By default, the # of reviews collected over the past 30 days. You can play with this to see how review velocity (the # of reviews you collect per month) can get you to your target faster.
• New reviews average rating: By default, the average rating of the reviews collected over the past 30 days. You can play with this to see how increasing your review rating can get you to your target faster.

It's generally safe to assume that if your review collection is too aggressive, you'll end up collecting "meh" reviews – which might hurt your average rating.

However if you're not being aggressive enough, you'll likely end up with a few 5 star reviews, and a few 1 star reviews from the occasional angry customer. Nobody can consistently provide a perfect experience.

The objective should be to experiment to figure out how aggressively you and your team should collect reviews to get to your target rating as early as possible.

Updated on: 30/07/2025