Process Flow
Animated overview of the full workflow
TL;DR
Looker Studio calculated fields let you create custom metrics not available in standard data sources. Common examples: ROAS (Revenue/Cost), CPA (Cost/Conversions), CTR (Clicks/Impressions×100), lead-to-sale rate, profit (Revenue - Cost), and blended CPA across platforms. Create calculated fields in the data source editor or at the chart level. Use CASE statements for conditional logic (e.g., campaign type labels) and mathematical operators for custom formulas.
Step-by-Step Guide
Follow these 5 steps to complete this guide
- 1
Creating Calculated Fields
In Looker Studio, go to your data source > Add a field > write your formula. Or click 'Add a field' within a chart for chart-specific calculations.
- 2
Common Formulas
**ROAS:** `Revenue / Cost` **CPA:** `Cost / Conversions` **Profit:** `Revenue - Cost` **Conversion Rate:** `Conversions / Clicks * 100`
- 3
CASE Statements
Use CASE for conditional logic: `CASE WHEN Campaign_Name CONTAINS 'Brand' THEN 'Brand' WHEN Campaign_Name CONTAINS 'Search' THEN 'Non-Brand' ELSE 'Other' END`
- 4
Blended Metrics
To calculate metrics across platforms (blended CPA, total spend), use data blending. Add multiple data sources and blend on a common dimension (date). Create calculated fields on the blended data.
- 5
Best Practices
Name calculated fields clearly. Document formulas. Test with known values to verify accuracy. Use calculated fields for metrics that your team actually needs — do not create everything possible, just what drives decisions.
Was this guide helpful?
Your feedback helps us improve our guides