Referencing Fields from Other Cards Using Single Card Field Formulas

By default, every field you create in Amazing Fields is shared across all cards on the board. This means a formula on any card can only see and use the other fields on that same card, it has no awareness of what is on other cards.

To change this, you need to tell Amazing Fields: "This field belongs to one specific card only." That is what the Single Card Field setting does.

For example, if you have a board with 20 expense cards and one summary card. You want the summary card to show a total. Before you can write that formula, Amazing Fields needs to know that the total field lives exclusively on the summary card. The Single Card Field setting is how you declare that.

Step One: Set up a single card field

Before you can reference data from other cards, you need to configure the field as a Single Card Field. This tells Amazing Fields that this field belongs to one specific card.

• Open Amazing Fields Settings by clicking the Amazing Fields icon in the top-right corner of the board.
• Select the field you want to use for cross-card calculations.
• Go to Card Display options.
• Set the Single Card Field option to the card this field should live on.

Step two: Build your formula using cross-card references

Once the field is set up as a Single Card Field, the formula editor gives you two additional reference types:

Card Field

+ Card Field when you want to pull the value of a specific field from one specific card.

For example: let's say you have a card with the number of hours you work per week. If you want to use that on other cards you reference it as a card specific value and pull it from that one single card.

List Field

+ List Field when you want to aggregate a field's value across all cards currently in a specific Trello list. Your formula can then do things like compute SUM, AVERAGE, MIN, and MAX across the entire list of values.

For example: let's say you have a 'Project Expenses' list with a 'Cost' field on each card. A summary card can use a List Field reference to show the running total automatically.

Examples

Sum costs across multiple specific cards

This example shows a 'Total Expenses' field set as a Single Card Field. The formula adds the 'Cost' field from three specific cards: Operations, Overhead, and Project Summary.

Sum All Values in a Trello List

This example shows a 'Proj Total' field set as a Single Card Field on a Project Summary card. The formula sums the 'Cost' field from every card in the 'Project List' list.

Combining Reference Types

You can mix Field, Card Field, and List Field references in a single formula. Think of your board like a spreadsheet, cards are rows, fields are columns, and formulas connect it all together.

• Use regular Field references for values on the same card.
• Use Card Field references for fixed values that live on a single source card.
• Use List Field references for running totals or aggregates across a whole list.