How to Use Lookup, Rollup & Count Fields
Once your tables are linked, lookup, rollup, and count columns bring the connected data in automatically. Show a field from a linked row, sum or average a number across many linked rows, or count how many are attached.
Step-by-step guide
Start from a link column
Lookup, rollup, and count all read through an existing Link to record column, so link your tables first if you haven't (see the linking guide). Each of these column types asks which link column to follow.
Add a Lookup to show a linked field
Add a column and choose Lookup (linked). Pick the link column to follow, then pick which field of the linked row to display. Example: on Tasks linked to Projects, look up the Project's Owner or Deadline so it shows right on each task.
Add a Rollup or Count to aggregate
Choose Rollup (linked) to aggregate a number across all linked rows, then pick the field and a function such as sum, average, min, or max. Choose Count (linked) to simply count how many rows are linked. Example: roll up the total hours of a Project's tasks, or count how many are still open.
Tips
- Link your tables first, lookup, rollup, and count all follow a link column
- Use Lookup to display a linked field, Rollup to aggregate numbers, Count to count relations
- Rollup functions include sum, average, min, and max
- Derived columns are read-only and refresh automatically when links or source values change
Frequently asked questions
What is the difference between lookup, rollup, and count?
Do I need linked records first?
Do lookup and rollup values update automatically?
Can I roll up across a two-way relation?
Related guides
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