With 123FormBuilder, you can perform calculations on your web forms & surveys. Use form calculations to add mathematical operations between your fields on your online forms.
First, you need to assign the values to your products/services. To do so, add a choice field (Single/Multiple choice or Dropdown field) and list the available choices.
Click the field to open its options in the left-side panel and select Price from Payment & Calculations section.
Next to each option type in their correspondent price.
After saving the prices, this is how it would look like. By default, the prices are shown on form, but you can disable that by toggling off Show prices on form.
If you need the user to type in a custom amount, add a Number field and assign the price “1”. By default, a field has no value assigned to it, meaning the input will be multiplied by zero.
By assigning a value, the form will calculate input value X 1. ( e.g user types 123, the number field will calculate 123 X 1= 123 instead of 123 X 0= 0).
When you are using a Number (input) field, it also works as a quantity field. Assign the full price to the field (e.g $150). If the user types 2, the calculation will be 2 X 150 = 300$.
To create mathematical operations on your form, add a Formula field. This field will show the total value in real-time.
Add a Formula field from the Specific fields section. A calculator will appear where you can add operations between your form fields. Use the Add field button within the calculator to add your form fields. Once the field is selected, it will be automatically added to the formula. You can use your keyboard to add operators and values.