Calculation fields, Lookup fields, and Relate Form fields are useful to streamline workflows and automate business logic, but to keep your system running smoothly and your data reliable, there are important limits you need to know. Here’s a simple guide to the key restrictions—and how to work within them.
1. Calculation Field
Calculation fields automate data processing right inside your forms. To ensure performance and stability, here’s what you need to keep in mind:
Quantity Limits
Per Form: You can add up to 100 Calculation fields to a single form.
Per App: An app can have up to 100 forms that contain Calculation fields.
Usage Limits
Reference Limit: All Calculation field formulas in one form can reference up to 20 different related forms.
No Mutual References: Calculation fields cannot reference each other. For example, if Field A’s formula uses Field B, Field B’s formula cannot use Field A.
Aggregate Variables: Each Calculation field formula can use up to 20 fields from the related forms. For each referenced form, you can configure up to 10 aggregate variables.
Subforms: Calculation fields can’t be added to subforms.
Automations: Changes to Calculation field values won’t trigger Automations, Automation Pro, or Webhook events.
2. Lookup Field
Lookup fields are crucial for connecting forms and pulling in data. Here are their main limits:
Quantity & Usage Limits
Per Form: Add up to 20 Lookup fields to a single form.
CRM Forms: Lookup fields can’t be added to CRM predefined forms.
Subforms: Lookup fields can’t be used as subform fields.
Deleting Related Forms: If a related form is used by an aggregate table or Calculation field, you must remove those references first before deleting the form.
Relationship Constraints
Maximum Associations: A form can be referenced by up to 100 other forms as a master form.
Self-Relation: Only one self-relation is allowed per form—you can’t set up multiple Lookup fields referencing the same form.
No Self-Association: In self-relation mode, a record cannot reference itself. The current record won’t appear in the selection list, ensuring data integrity.
Configuration Restrictions
Avoid Circular References: Don’t create loops between Calculation and Lookup fields. For example:
If the Calculation field X from the master form is filled into the Lookup field Y in a related table, referencing Y in X’s formula will cause an error.
If the Calculation field X references the field Y, then filling X into Y will also cause an error.
3. Relate Form Field Usage
Relate Form fields enable complex relationships and batch operations. Here’s what you should know:
Subforms: Relate Form fields cannot be added to subforms.
Batch Addition: Only one Relate Form field per form can be set to “Add together with the data in the master form,” allowing you to add up to 500 related records at once.
By understanding and respecting these limits, you’ll build more reliable, scalable, and efficient apps. Plan your forms thoughtfully, avoid circular references, and use these powerful features to their fullest—without hitting technical roadblocks.
Ready to take your data modeling to the next level? Keep these best practices in mind and unlock the full potential of Calculation, Lookup, and Relate Form fields!