Write formulas in Metric Explorer

A formula in Metric Explorer is arithmetic on other metrics in the same chart, such as A/B for a ratio or (A+B)/C for a combined rate. Each input keeps the measurement, filters, and group-bys set on its own metric, so the formula itself stays short. A formula that mixes an event metric and a session metric is a hybrid formula, for example revenue per session or add-to-carts per session.

Write a formula

1. Add the metrics the formula uses, for example Page Viewed measured as Event Totals and [Amplitude] Any Active Event measured as Total Sessions.
2. Click fx. A Formula card appears in the Metrics block.
3. Enter the expression using the metric letters, for example A/B.
4. Optional: click Name formula in the formula's ⋮ menu and enter a name, such as Pages per session. The name replaces the expression in the legend and breakdown table.

Amplitude hides the metrics a formula refers to, so the chart shows the formula's result. To show an input next to the formula, open that metric's ⋮ menu and click Show in results.

Formula syntax

• Letters: Each metric in the Metrics block has a letter by position: A, B, C, and so on. Formulas and session metrics take letters too, so a metric added after a formula in position C becomes D.
• Operators: Use +, -, *, /, and parentheses, for example (A+B)/C.
• Percentages: Start the formula with %: to display the result as a percentage, for example %:A/B for a conversion rate.
• Segments: With more than one segment, add the segment number after the letter. A2/A1 divides metric A in segment 2 by metric A in segment 1.

Measurements come from each metric, not from functions in the formula. Where an Event Segmentation formula reads UNIQUES(A)/TOTALS(B), a Metric Explorer formula reads A/B, with A measured as Unique Users and B as Event Totals. For smoothing, set Rolling Average, Rolling Window, or Cumulative on an event metric from its ⋮ menu.

Hybrid formulas

A hybrid formula combines event inputs and session inputs in one expression. Use one when the question relates actions to visits:

A formula can also divide two session metrics. For example, the share of sessions with a purchase is %:A/B, where A is Purchase measured as Total Sessions and B is Total Sessions of all sessions.

Inputs keep their own filters, so a hybrid formula can compare a filtered event with all sessions. For example, divide revenue where plan is pro by all sessions.

Hybrid formulas run in Metric Explorer and in Data Tables, and you can save them as metrics for either.

Create a hybrid formula in a Data Table

1. In a Data Table, open the Metrics tab and click + Define new Metric.
2. Choose Hybrid Formula as the metric type.
3. Add event and session inputs. Each input has a letter and its own Measured as.
4. Enter the expression, for example A/B.
5. Click Save and Close.

For other metric types in Data Tables, go to Create a metric.

Filters and group-bys with formulas

A formula uses the filters and group-bys of its inputs. To break a formula down by a property, add the same group-by to each input. The formula then renders one series per value. For session inputs, the group-by also chooses which session value to use. Go to Group sessions by entry, exit, or any value.

In Data Tables, global filters apply to both event and session inputs of a hybrid formula. For session columns, go to Use session metrics in Data Tables.

Save a formula as a metric

Save a formula as a metric to reuse it in other Metric Explorer charts and Data Tables and to keep one definition across your team.

1. On the formula, or on any metric, open the ⋮ menu and click Save as Metric. To save the whole chart as one metric, open More above the chart and click Save as Metric.
2. Review the metric definition. A formula with event and session inputs saves as a Hybrid Formula metric.
3. Name the metric and save it.

The saved metric appears in the metric picker of Metric Explorer and Data Tables. For managing saved metrics, go to Metrics.