Free Google Review Calculator

This free Google review score calculator uses the weighted average formula to determine how many 5-star reviews you need. If you have N total reviews with a current average rating of R, and you want to reach a target rating of T, the number of five-star reviews needed is:

Example: With 80 Google reviews at a 4.2 average, to increase your rating to 4.5:
= ceil( 80 × (4.5 − 4.2) ÷ (5 − 4.5) )
= ceil( 80 × 0.3 ÷ 0.5 )
= ceil( 48 ) = 48 five-star reviews needed

This Google review rating calculator works for any starting point. Whether you're at 3.5 stars trying to reach 4.0, or at 4.7 aiming for 4.9 — the math adapts to your exact situation.

Google displays your review rating rounded to the nearest tenth. This means to display 4.5 stars, your raw average must be at least 4.45. To display 4.8, you need at least 4.75. This is why our Google review star calculator accounts for display thresholds — small differences in raw score can change what customers actually see.

Important: Google may also apply recency weighting, meaning recent reviews could have slightly more impact on your displayed score. The Google review average calculator here uses the standard weighted average, which is accurate for the vast majority of businesses. For the most precise calculation, use the "exact mode" star breakdown above.