# How to Calculate Cosine Similarity in Excel

Cosine Similarity is a measure of the similarity between two vectors of an inner product space.

For two vectors, A and B, the Cosine Similarity is calculated as:

Cosine Similarity = ΣAiBi / (√ΣAi2√ΣBi2)

This tutorial explains how to calculate the Cosine Similarity between vectors in Excel.

### Cosine Similarity Between Two Vectors in Excel

Suppose we have the following two vectors in Excel: We can use the following formula to calculate the Cosine Similarity between the two vectors in Excel:

```=SUMPRODUCT(A\$2:A\$9,B2:B9)/(SQRT(SUMSQ(B2:B9))*SQRT(SUMSQ(\$A\$2:\$A\$9)))
```

The following screenshot shows how to use this formula: The Cosine Similarity between the two vectors turns out to be 0.965195.

Note that we interpret the value for Cosine Similarity as follows:

• A value of -1 indicates maximum dissimilarity
• A value of 0 indicates that the two vectors are orthogonal
• A value of 1 indicates maximum similarity

A value of 0.965195 indicates a high level of similarity between the two vectors in our example.