Here we're going to look at how to build a single item order form that also contains a quantity to automatically calculate the end user's total. To build a single item order form where the user chooses a quantity, we'll start by creating a new form and giving it a title. For this example form, we're going to be selling copies of a book, so the Form has been titled "Book Order Form".
Next, add fields for Name, Email, Phone, Mailing Address and any other fields you need to collect from the end user to process each order. To add those default fields to your form, just drag and drop them over to your form from the form builder toolbox on the left in Build mode.
After that, we want to add a Number field to the Form to represent the Price for each Book. In this example, we added a Number Field and titled it "Price Per Book". It's important to set this field to "Read-Only" so the end user's cannot edit or delete the price per book. Since the user doesn't need to see this field, you can check the "Hidden" checkbox to make it hidden on the form, however, this is optional.
In the "Price Per Book" field, you will want to enter the price per item in the "Default Value" box. It's important not to add currency values, punctuation, etc. directly in the field, rather you will want to insert just the cost for the item. If you want to add a currency notation to the field, you can choose a currency option form the Currency drop down menu. For this example, the price is "5" and I set the currency to "$" and the field to "2" decimal places.
After saving the Price field, we will need to add a Dropdown List/Select List field titled to collect the quantity, which will be used to calculate the end user's cost. In the Dropdown List field editor, add the available quantity options. Our options will be "1, 2, 3, 4, 5," with each number on a separate line. You may add as many quantity options to the field as you would like.
The last field you will want to add is a Number field to calculate the final Total. This field should also be set to "Read-Only" to ensure the value does not get altered or deleted. In the field editor, click the "Use Calculation" option under the Default Value field. In the calculation body field, choose the "Price Per Book" field from the "--Field--" drop-down menu, insert a multiplication symbol and then insert your quantity field - mine is titled "How Many Books Would You Like to Order?". I also set this field to "2" decimal places and set the currency to "$".
Now that we have our form built, we need to add a third-party payment processor. They all work similarly, but PayPal is the most common one used, so for this example, we will use PayPal Website Payments Standard. To add the PayPal integration, go into the Form > Settings > Integration Hub > Payments > click the Add button next to PayPal.
With the payment processor added, map the fields from the Form to the integration making sure your "Total" field is mapped to the payment processor Total or Price field. This will tell the payment processor how much to charge the user after they've selected the number of items they are purchasing.
Below is an example of what the Published form will look like:
When I choose a Quantity of "2" and submit the form, I will be redirected to PayPal and my Total of $10 ($5 per book x 2 books) will be transmitted and displayed.
Your end-users will be able to pay via PayPal or credit card.