Update Calculation is a WordPress ability from Ninja Forms — usable via Easy MCP AI, which connects Claude, ChatGPT, and any AI assistant to your site.
Install Free Plugin →Update Calculation
WriteUpdate an existing calculation's formula or number formatting.
Requires the Ninja Forms plugin on WordPress 6.9+ for the Abilities API (all 32 abilities are registered only when the wp_register_ability() function exists, via NF_Abilities_Integration::load_abilities_api() running on plugins_loaded). Every ability is gated by the same ninja_forms_ability_can_manage_forms() permission callback, requiring the caller to hold WordPress's manage_options capability or Ninja Forms' own nf_edit_forms capability.
What it does
This ability updates a form's named calculation, identified by form_id and name, changing its formula and/or decimal formatting (decimal_places, decimal_point, thousands_sep). Only supplied fields are changed. Field keys referenced in the formula must exactly match the form's actual field keys — retrievable via ninjaforms/get-form — or the calculation will silently fail or return zero, so an AI assistant should verify keys before editing a formula on the user's behalf.
See it in action
You ask your AI assistant
"Update the 'total' calculation on form 12 so it also adds the shipping field before applying tax."
Inputs
| Name | Type | Required | Description |
|---|---|---|---|
| form_id | integer | Yes | The numeric ID of the form. |
| name | string | Yes | The name/key of the calculation to update. |
| formula | string | No | New equation using {field:key} and {calc:name} references. |
| decimal_places | integer | No | Number of decimal places for the result. |
| decimal_point | string | No | Decimal point character. |
| thousands_sep | string | No | Thousands separator character. |
Returns
An object with a 'success' boolean, the 'form_id', the calculation 'name', an 'updated' count, and a 'message'.
Permission
The current user must have WordPress's 'manage_options' capability or Ninja Forms' own 'nf_edit_forms' capability (checked via the shared ninja_forms_ability_can_manage_forms() permission callback).
More Ninja Forms abilities
Add Action
Add a post-submission action to a form — email, redirect, success message, or save.
Add Calculation
Add a calculator formula to a form for use in calc fields and conditional logic.
Add Field
Add a single field to an existing form, to be called once per field when building out a form.
Create Form
Create a new Ninja Forms form, optionally with fields, actions, and calculations, in a single call.
Delete Action
Permanently delete an action from a form.
Delete Calculation
Permanently delete a calculation from a form.