Subitem Rollup References
Aggregate subitem column values in parent item formulas using Subitem's syntax, with SUM, AVERAGE, MAX, MIN, COUNT, CONCATENATE, and MEDIAN.
Parent items can aggregate values from their subitems — summing hours, averaging scores, collecting names into a list. This is called a rollup: a formula on the parent item reads data across all its subitems and produces a single computed value.
Subitem's Syntax
Use the Subitem's prefix to reference a subitem column inside a parent item formula:
{Subitem's Column Name}Wrap it in one of the 7 supported aggregation functions:
SUM({Subitem's Hours})
AVERAGE({Subitem's Score})
MAX({Subitem's Priority Number})
MIN({Subitem's Due Date})
COUNT({Subitem's Amount})
CONCATENATE({Subitem's Name}, ", ")
MEDIAN({Subitem's Budget})The formula evaluates once per parent item, collecting the referenced column value from every subitem and feeding them all into the aggregation function.
This is a parent board formula. Set it on a column in the parent board, not the subitem board. Subitem column values become inputs — your formula reads from them and writes the aggregated result to the parent column.
The autocomplete in the formula editor lists all available subitem columns with the Subitem's prefix — start typing {Subitem's to see suggestions.
You can also reference each subitem's name:
CONCATENATE({Subitem's Name}, ", ")Supported Aggregation Functions
Subitem references must appear inside one of these 7 functions:
| Function | Returns | Use it for |
|---|---|---|
SUM({Subitem's X}) | Number | Total hours, total cost, total points |
AVERAGE({Subitem's X}) | Number | Average score, average rating, average hours |
MIN({Subitem's X}) | Number | Earliest value, minimum score |
MAX({Subitem's X}) | Number | Latest value, highest score |
COUNT({Subitem's X}) | Number | How many subitems have a numeric value |
CONCATENATE({Subitem's X}, ", ") | Text | Comma-separated list of names or labels |
MEDIAN({Subitem's X}) | Number | Middle value in the distribution |
SUM, AVERAGE, MIN, MAX, MEDIAN, COUNT work on numeric subitem columns (Numbers, Rating, Time Tracking properties). CONCATENATE collects text values across subitems and joins them with the separator you provide.
For a full description of each function, see Function Reference.
What Columns Can Be Referenced
Any extractable subitem column type works inside a rollup:
| Subitem Column Type | What Gets Aggregated |
|---|---|
| Numbers | Numeric value |
| Rating | Numeric rating (0 if not rated) |
| Time Tracking | Use a property: {Subitem's Time Tracking#Hours} |
| Status | Status label (text) — use with CONCATENATE |
| Text | Text content — use with CONCATENATE |
| Long Text | Text content — use with CONCATENATE |
| Date | Date string (YYYY-MM-DD) — use with MIN or MAX |
| People | Use a property: {Subitem's Assignee#Names} |
| Dropdown | Use a property: {Subitem's Category#Labels} |
| Name | Subitem's own name: {Subitem's Name} |
Properties work with subitem references. Use hash notation just like regular columns: {Subitem's Time Tracking#Hours}, {Subitem's Assignee#Names}, {Subitem's Category#Labels}.
Not supported: Mirror, Formula, and other computed column types — same restrictions as regular source columns (see Supported Columns).
Empty and Missing Values
When a subitem has no value in the referenced column, aggregation functions handle it gracefully:
| Aggregation Type | Empty subitem value treated as |
|---|---|
| SUM, AVERAGE, MIN, MAX, MEDIAN, COUNT | 0 |
| CONCATENATE | "" (the subitem is skipped in the output) |
If a parent item has no subitems at all, rollup formulas return 0 for numeric targets and "" for text targets — the target column is cleared.
Auto-Aggregation for Text Targets
When your target column is Text or Long Text, you can use a bare subitem reference without wrapping it in a function:
{Subitem's Task Name}Formula Trigga automatically collects all subitem values and joins them with ", ". The result is equivalent to:
CONCATENATE({Subitem's Task Name}, ", ")This is convenient for quickly listing subitem names or labels in a parent text column.
Auto-aggregation only works for Text and Long Text target columns. For Numbers, Date, Status, or other column types, you must use an explicit aggregation function — for example, SUM({Subitem's Hours}) instead of a bare {Subitem's Hours}. If you use a bare reference with an incompatible target column, the formula editor will show an error at save time.
How Rollup Recalculates
Rollup formulas recalculate automatically whenever:
- A subitem column value referenced in the formula changes
- A subitem is added to or removed from the parent item
- A subitem is renamed (if
{Subitem's Name}is referenced)
The update is event-driven — the parent column recalculates within seconds, and any automations watching it fire immediately.
Limitations
- Parent board formulas only. Rollup references (
{Subitem's ...}) work in formulas on the parent board. Subitems cannot reference other subitems' columns. - No nesting. You cannot nest subitem references —
SUM(SUM({Subitem's X}))is not valid. - One level only. You cannot roll up from grandchild items (subitems of subitems are not supported).
Next Steps
- Recipes and Patterns — ready-to-use formulas including subitem aggregation examples
- Parent Column References — reference parent item data in subitem formulas
- Supported Columns — target columns, source columns, and column properties
Parent Column References
Reference parent item columns in subitem formulas using Parent's syntax, with automatic sync on parent changes.
Recipes and Patterns
Six ready-to-use formulas for common monday.com workflows — conditional status, due dates, notifications, subitem inheritance, time tracking, and division-safe calculations.