Selling product by the square foot

Hello, we sell products by the square foot. How can I use your form with the following formula?

Total square feet: 100 x $29 = $2,900

Thank you for your help.

Hi Stéphane,

Thanks for reaching out to Jotform Support. Note that the total amount will be automatically as soon as you connect the Product List to your favorite payment platform. TO connect it, just click on the Credit Card icon of the Product List element shown below.

Then, once connected to the payment platform, the Total amount is displayed in the live form, as well as the payment information required, depending on the select payment gateway:

You might also want to check out this guide Introducing a new product list form field.

Give it a try and let us know how it's going.