**coachderemer**I have only one product. it cost $35.

I want to have the user enter a quantity in a number field, then (using PayPal payment) multiply the product cost by the number entered. Then this is the total cost and sent through Paypal.

Example:

Number Field - entered 3

in the PayPal (only one product at a cost of $35), 3 x $35 totals $105. The $105 is processed via PayPal.

https://www.jotform.com//?formID=62705265142956

**sevkiyontem**Hello, there is a page that defines how to pass a calculation to a payment field.

At first you need to calculate the amount.

If you try those and have problems with your form, please write here again.

I hope you can solve the issue.

Cheers.

- JotForm Support
**Nik_C**I checked your form and I see that it is multiplying the quantity and product's price:

What sevkiyontem said is correct, here is more detailed instruction if you want more customized product list:

1. Create one Form Calculation field in the form:

2. Add one text box for quantity and one checkbox for your product:

3. Now we will set that checkbox value is 35:

Go to Setting of the checkbox field:

And set Calculation value to 35:

4. In the form calculation, we will jus do the actual multiplying of the product and quantity:

Go to wizard of the form calculation:

And just multiply your checkbox with quantity field:

5. Finally, we will pass Form calculation field to PayPal:

Hope it helps.

Let us know if you need further assistance.

Thank you!