Displaying calculated fields in Kibana 4

Kibana 4 supports scripted fields. You can add calculated fields and use them in visualizations. Scripted fields use the Lucene expression syntax.

From Kibana documentation:

You can reference any single value numeric field in your expressions, for example:

doc['field_name'].value To create a scripted field:

1. Go to Settings > Indices
2. Select the index pattern you want to add a scripted field to.
3. Go to the pattern’s Scripted Fields tab.
4. Click Add Scripted Field.
5. Enter a name for the scripted field.
6. Enter the expression that you want to use to compute a value on the fly from your index data.
7. Click Save Scripted Field.