Is there a functionality to have the sum of a numbers column in sub-items be totalled in a numbers column in the top line task?
I have a board tracking high level project timings for our technology team, with all the usual information, including a numbers column to state the number of manhours that project will take. This is for resourcing planning using a Workload widget.
Some of these projects need to be broken down into smaller tasks via sub-items, again, with each having its manhour resource defined.
I’d like to have an automated rule or formula to sum up that numbers column in the sub-items and total it in the top line task. There’s no automation that I can currently find to achieve this, so I’m wondering if theres a work around or formula to make this possible?
Great question! As Bas mentioned, the native “Summary on Parent Item” option has some real limitations — it creates a mirror-type
column you can’t use in formulas, dashboards, or the Workload widget, and it breaks for parent items without subitems.
SubItems Pro solves this cleanly with its Rollup Sync feature — here’s how it would work for your manhours tracking:
Setup (takes about 30 seconds):
Add SubItems Pro as a Board View on your project board
Open the Rollup view and create a rule:
Source: your subitems “Manhours” column
Function: SUM
Target: your parent item “Manhours” column (a regular numbers column!)
Toggle on Auto-Sync — that’s it
What happens next:
Every time a subitem’s manhours value changes, the parent total updates automatically in the background
It writes to a real numbers column, so it works perfectly with your Workload widget, formulas, dashboards, and automations
No mirror columns, no workarounds
Beyond SUM, you also get:
AVG / MIN / MAX / COUNT — for numbers columns
Status rollups — e.g., show “Done” on parent only when all subitems match
Date rollups — earliest/latest dates across subitems
Timeline rollups — auto-span parent timeline from subitem date ranges
Multiple rules per board — so you can roll up manhours, status, and dates all at once
And if you ever need to bulk-manage subitems themselves, SubItems Pro also handles:
Bulk Create subitems across multiple items (with value inheritance from parent)
Clone subitems from one item to others
Bulk Edit subitem column values across items in one go
