How do i set up the calculation on the sponsorship form?

Hello,

How do i set up the calculation on the sponsorship form? is it the same as how I did vendor calculations?

You can do it the same way if you want to:

1) Assign values to the options the user will select: https://www.jotform.com/help/301-How-to-Assign-Calculation-Value 

2) Perform the calculation using the Form Calculation widget: https://www.jotform.com/help/259-How-to-Perform-Form-Calculation-Using-a-Widget 

3) Pass the total to your payment field: https://www.jotform.com/help/275-How-to-Pass-a-Calculation-to-a-Payment-Field 

However, you could simply set the 3 products in your payment field directly: https://www.jotform.com/help/165-Setting-Up-Your-First-Order-Form 

Let us know if you need more help.