Thread: Need help with shipping in my shopping cart

I am trying to figure out how to accurately calculate shipping on my site. I don't want to have to do standard shipping (per sku) because that can add up quick. I can't charge by order sub-total so I need to know, what is Custom PHP Include, and if I can't use that how do I do the offline/manual option. I know how to set it to that, but I don't get how it works once customers submit the order. If they go to PayPal with a total that does not reflect shipping (which they do as soon as the order is placed), then how do I ensure that they are paying the correct amount? They won't get the correct amount before they choose the payment method because I have to email them the correct amount. Make any sense?!?!?

I would check ups.com of fedex.com and see if they have a utility where people can enter their zip to calculate the shipping. I would think they would offer it.