Calculate totals from a gallery collection
Learn how to use Power Apps Calculate totals from a gallery collection with practical Power Apps guidance, implementation steps, common mistakes, troubleshooting, and related BuilderVault patterns.
What this pattern solves
Power Apps Calculate totals from a gallery collection is a practical BuilderVault pattern for makers and developers who need a repeatable way to handle calculate totals from a gallery collection inside a real Microsoft business app. The goal is to move past trial-and-error and give the builder a clear structure they can adapt to their own screens, flows, lists, tables, or environments.
Use this page when you are deciding how the pattern should work, what supporting data or permissions are needed, and what should happen when the happy path fails. The notes below focus on implementation fit, common mistakes, troubleshooting, and internal links to adjacent patterns so the build stays consistent.
Search intent
Help a Power Platform builder understand when to use Power Apps Calculate totals from a gallery collection, how to implement it, and what mistakes to avoid before using it in a production business app.
Problem
Users need live totals while editing rows before those rows are saved to SharePoint.
What the finished pattern should include
- A maker can explain the control, formula, validation, and save behavior before release.
- The app gives users clear feedback for successful saves, missing values, and failed updates.
- The pattern can be handed to another builder without relying on hidden assumptions.
Solution
// Calculate totals from the current gallery or filtered collection
ClearCollect(
colVisibleRequests,
galRequests.AllItems
);
Set(varTotalAmount, Sum(colVisibleRequests, Amount));
Set(varOpenCount, CountRows(Filter(colVisibleRequests, Status.Value <> "Complete")));
Set(varHighPriorityCount, CountRows(Filter(colVisibleRequests, Priority.Value = "High")));
// Use labels:
// Text(varTotalAmount, "$#,##0.00")
// varOpenCount & " open requests"Implementation checklist
- Confirm the Power Apps scenario and the business user this pattern supports.
- Identify the data source, owner, security model, and exception path before building.
- Build the smallest reusable version first, then add optional branches or polish.
- Test with realistic data, permissions, edge cases, and handoff expectations.
- Link this pattern to its collection, topic hub, and related implementation patterns.
Step-by-step instructions
- Confirm which gallery or filtered collection represents the records users can currently see.
- Collect the visible rows into a local collection before calculating totals that drive labels or summary cards.
- Use Sum, CountRows, and Filter against the local collection so the displayed totals match the screen state.
- Test with no rows, one row, filtered rows, and records with blank numeric values.
When to use
- Budget rows
- Effort estimates
- Checklist completion counts
When not to use
- Authoritative finance calculations needing server-side control
Common mistakes
- Summing text inputs without converting to numbers.
- Calculating from gallery controls instead of the collection.
Troubleshooting
- If totals do not update, confirm Patch(colEstimateRows, ThisItem, ...) fires on control change.
FAQ
When should I use Power Apps Calculate totals from a gallery collection?
Use Power Apps Calculate totals from a gallery collection when the same Power Apps scenario is likely to appear in more than one app, flow, list, table, or environment and needs a repeatable implementation approach.
Does this pattern work with Power Apps?
Yes. This pattern is written for Power Apps scenarios, but you should still confirm connectors, licensing, permissions, delegation limits, and environment rules before using it in production.
What usually causes this Power Apps pattern to fail?
The most common failure points are unclear ownership, missing validation, weak exception handling, undocumented permissions, and testing only the happy path.
Is Power Apps Calculate totals from a gallery collection beginner friendly?
This pattern is rated Beginner. Beginners can use the fit guidance and checklist first, while experienced builders can move directly into the formula, flow, schema, or governance details.
Related patterns
Save gallery rows as JSON in a multiline text field
Store a lightweight editable table from Power Apps in one SharePoint item.
Patch a collection of checklist items
Save checklist rows from Power Apps to a SharePoint child list.