# Ratio metrics

Ratio metrics allow you to calculate ratio of two simple metrics, providing deeper insights into the relative performance of variations. This enables a more nuanced analysis of experimental results, allowing businesses to understand the impact of changes in a more comprehensive manner.

For example, consider an *average order value* metric, which is created by dividing revenue (sum of prices) by number of orders (*sum* of items purchased or *count* of prices).

Ratio metrics are computed by first computing averaged values for the numerator and the denominator, and then dividing them to compute the ratio, rather than computing the ratio on a user level and then taking the average.

We use the Delta method to compute valid statistical results for ratio metrics.

## Creating a ratio metric

Creating a ratio metric follows the same approach as creating a simple metric. Of course, the difference is that for a ratio metric, you have to select both a fact and aggregation for numerator and denominator.