Real Time Shipping Calculators allow you to utilise the APIs (Application Programming Interface) of your shipping Company to determine what it will cost to to ship the items in the customer's shopping cart to them. There are a few advantages to this method rather than manual entry including :-
- No need to fill in the shipping costs manually.
- No need to update the shipping costs manually when they change.
- The rate will always be correct as it is pulled from your account with the shipping Company.
- No need to overcharge your customers on shipping costs to compensate for shipping cost miscalculation.

Below is a list of shipping Company APIs that Viper Cart supports or that we are currently working on.

Below are some examples of what your customers would see when they want to find out the cost of shippng.

Cart Estimation	Checkout Final Costs