# Metrics formulas

You can combine metrics into formulas to get additional insights.

For example, compare an error count metric to the overall count, to determine error percentage.

Here, we start with the side-by-side metric display of `aws_logs_call_count` and `aws_logs_error_count` demonstrated in [Add query](https://docs.kloudfuse.com/platform/3.2.5/metrics-queries/#query-add) and [Separate queries](https://docs.kloudfuse.com/platform/3.2.5/metrics-queries/#separate) sections.

## Add formula

You can combine metrics over facets or labels into formulas, to get additional insights.

1. To add a formula, click  (Add Formula).

2. The empty formula option appears in interface as line  (1), under the query lines.

3. Type the formula in the text box next to label  (1).

Here, use ba100ba100 to calculate the percentage of errors across the time series.

4. The interface displays graphs for both queries and the new formula.

5. The error percentage chart is a starting point for creating a new alert. See [Metric alerts](https://docs.kloudfuse.com/platform/3.2.5/metric-alert/) and [Create alerts](https://docs.kloudfuse.com/platform/3.2.5/alerts-create/).

## Remove a formula

1. To remove a formula, click  (Delete) icon that corresponds to the formula you plan to remove.

2. The formula is no longer in the interface.