The rollup allows you to perform a calculation on an entire column or a Relation. The most basic computation for the rollup is Count.

For example, in the image below we create a rollup column that counts the number of items in the `Animals`

column. The result is a number: the total number of animals that fit that parameter.

## Column or relation source

For example, in the app below we have a list of people who all have tasks. The `Tasks`

column is a relation that pulls in every task assigned to each individual person. We can then create a rollup column that counts the total number of tasks for each person.

To create a rollup column:

- Open the data editor and add a new column.
- Label your column and select “rollup” as the column type.

- Choose with existing column or relation you want to perform your calculation on.

- Choose which calculation you want to perform.

- Specify the precision in decimal points for your calculation, as well as if you want to use a group separator or add units to the calculation.

- Select Done, and you will immediately see your calculations fill the column.

## Calculations

The Rollup Column can perform different calculations based on the data it finds in the column or relation you select.

### Numbers

The rollup column can calculate the Count, Count Unique, Sum, Average, Range, Minimum, and Maximum of number values.

### Dates

The Rollup Column can calculate the Count, Count Unique, Earliest, and Latest of date values.

### Boolean

The Rollup Column can calculate the Count, Count Unique, Count True, Count False, All True, and Some True.

### Text

The Rollup Column can calculate Count or Count Unique.