Maybe you’re a business owner looking to allow users to calculate the price of your products right from your form. Or maybe you’re just looking to have an awesome calculator that performs specific operations.
The Everest Forms Calculations addon allows your users to perform calculations based on their input on targeted fields and display the result.
Installation #
- Firstly, you need to purchase the Everest Forms Pro plugin.
- After the successful purchase, you will get the plugin zip file under your WPEverest account page.
- Now, you can download the Everest Forms Pro plugin and Calculations add-on from there.
- Through your WordPress Dashboard, visit Plugins -> Add New -> Upload and then choose the downloaded zip file, and then install and activate it.
- Now you are ready to use this add-on for your site.
Alternative Method:
- Once you have entered the Everest Forms Pro license on your site, go to Everest Forms > Add-ons.
- Search for the ‘Calculation‘ add-on.
- Click on ‘Install‘.
- Once the installation is finished, click on ‘Activate‘. The add-on will be activated.
Setup and Configuration #
Once you’ve completed the installation process, let’s see how to set it up and work with it.
Enabling Calculation #
- First, add one or more Number fields for input. (There are more input fields that you can use. You can find them here.
- After that, insert another Number field to display the calculation result
- Go to its Field Settings and toggle the Enable Calculation On for the field.

For example, in the above form, Number Field A and Number Field B are used for the input of the numbers and Number Field A+B is used for the output where we will have to enable the calculation.
Note: You can only enable calculations on the Number and Single Item field to display the results.
Calculation Settings #

- Decimal Places: The Decimal Places field allows you to set the number of decimal values to be shown on the result. For example, suppose the result is 3.1413 and you’ve selected 2 in Decimal Places. Your result will be 3.14.
- Expression Field: This is the blank space where all the calculation expressions are to be set. It supports 26 operators and 2 parentheses “()”. And in this field, there are two buttons, Shortcut List on the left and <> on the right.
- Shortcut List: When you click the Shortcut List, it displays a list of operators that you can use on the Expression Field to create your formula or expression. If you select the operators from the list, it’ll be inserted on the Expression Field.
Expression #
The blank field on the Calculation settings is where the expression is to be set. For adding an expression, click on the <> button which will show the list of calculation-ready fields.

Available Operators
Mathematical Operators
- /: Division
- *: Multiplication
- +: Addition
- -: Subtraction
Conditional Operators
- if(): Execute something when the condition inside the if() block is true
- elseif(): Execute something when the condition inside the if() is false and the condition inside the elseif() is true.
- else(): Execute something when the conditions inside the if() and elseif() are false.
Example of Conditional Operators:
if ($FIELD_1==10):
0
elseif($FIELD_1==5):
2
else:
1
endif;
Here, if the input in the targeted field is 10, 0 is displayed on the result. If the input is 5, 2 is displayed. Any other input results in 1.
Mathematical Functions
- abs(): Returns the absolute value of any given number.
- average(): Returns the mean or average between a set of numbers.
- ceil(): Rounds a number up to the nearest integer.
- exp(): Returns e raised to the power of the given number.
- floor(): Rounds a number down to the nearest integer.
- ln(): Returns the natural logarithm of any number.
- log(): Return the base -10 logarithm of different numbers:
- max(): Returns the highest value among the input arguments.
- min(): Returns the lowest value among the provided arguments.
- num(): Converts a given value to a number.
- pi(): Returns the value of π.
- pow(): Returns the result of raising a number to the power of another number.
- rand(): Returns a random number, usually between 0 and 1, or within a specified range.
- round(): Rounds a number to the nearest integer or to a specified number of decimal places.
- sqrt(): Returns the square root of a number.
String and Text Functions
- trim(): Removes whitespace from the beginning and end of a string
- truncate(): Returns the first length characters of the string.
- concat(): Combines two or more strings into one string.
<>: When you click the <>, it displays available input fields that you can use in expression or formula.
List of Fields that can be used
- Single Line Text
- Dropdown
- First Name
- Last Name
- Number
- Multiple Choice
- Website/URL
- Range Slider
- Payment Checkboxes
- Payment Total
- Payment Multiple Choice
- Payment Single Item
Valid and Invalid Expressions:
When you add an expression with correct operator signs and fields, the ‘Formula is valid‘ message is shown below the expression field. .

Otherwise. the ‘Formula is invalid’ message is shown as below.

What to Avoid? (Invalid Expressions)
- The ^ sign is replaced with pow(). If you were previously using the ^ operator for returning the power of a number, you’ll now have to do so with the pow() function.
- Operators not listed on the Shortcut List.
Creating a BMI Calculator #
Let’s create a simple calculator to show you how easy it is. We’ll create a BMI calculator that calculates the Body Mass Index of any user based on their height and weight.
Here are the steps:
- For this, we’ll add three number fields. Rename it as height, weight, and result.
- On the result field, we’ll enable calculations.
- Then enter the BMI formula which is (kg/m ²).
- Make sure to press the Validate Formula button to ensure your formula is correct or not.
- If yes, simply save the form and test it.

RESULT:

Calculation on Payment Fields #
Running an online store or business is a piece of cake. Your customers can place their orders and view the total amount to be paid for.
To do so, you can use Single Item, Multiple Choice, and Checkbox payment fields.
- Single Item: Display an individual item and its price on the form. A fixed price is to be added to the purchase.
- Multiple Choice: Display an array of choices where only one item can be bought.
- Checkbox: Display a list of choices where users can select multiple items at once.
Payment Example #
Let’s create a form in which users can rent one of your vehicles. We’ll include the following fields:
- Payment Multiple Choice to pick their choice of vehicle.
- Range Slider to determine the time of the lease.
- Multiple Choice if they want the vehicle to be delivered to their location.
- Address and Single Item if they select “Yes”. This will display the field where users can enter their address, and a delivery charge will be added. Apply Conditional Logic for this.
- Number to calculate the total cost.
We’ll use if(), else(), multiplication, and addition. The if() condition checks whether the user agreed to delivery. If yes, the address and delivery charge field will be displayed. If not, they will be hidden and only the rent of the car and time will be multiplied.

RESULT
