Form variables stand in for hidden calculated values, can be bound to columns, and can be used as references in other runtime expressions like calculated value controls and rules.

There are different types of forms and templates that you can use for the variable field, like a personality quiz, area calculator, donation form, BMI test, etc.

Let's take calculating a circle area for our example. The form will calculate the circle area based on the formula and the radius “variable” entered by the user. The form includes variables, logic, and calculation to give the right answer automatically, based on the users’ answers.

For this, we should add 3 fields:

To create a form with those fields, open your dashboard and create a new form. Now click on "+ Add new field" to add fields to your form.

For the variable field, choose the type of variable as a formula and add an ID "area" to it.

For the variable fields' Default Value, you can write the formula that you want to calculate and use in your form.

In this case, we will write "radius*radius*3.14159265359" because of the formula

A=(r*r)π.

To pass a variable field value to another field in the form, you should use the answer piping feature.

With answer piping, you can easily pipe the calculated amount of circle area in the section field. Just add the variable field’s ID inside the content field as: {{area}}

You can find other examples of variable fields in our tutorials;

Templates:

BMI calculator

Personality quiz

Donation form