Shipping App that lets me customize product weight by transit time

[angiepi]

Hello,

I am in need of the right app that will let me input shipping parameters based on how many days it will travel and zip codes. I ship perishables and I need Shopify to be able to auto-calculate how much dry ice to add.

For example.

If customer chooses 2 day shipping - Add 2.5 lbs of dry ice to the base weight ( 20lbs + 2.5 lbs of dry ice = 22.5 lb shipment )

If customer chooses 3 day shipping - Add 5 lbs of dry ice to the base weight ( 20lbs + 5 lbs of dry ice = 25 lb shipment )

The problem that I am facing right now is that I have to set the weight of my products to the heaviest weight. It is set to 27 lbs. The downside to this is that, I am charging all my customers throughout the US the same weight with a markup. If someone chooses 2 day shipping, the weight of the products is only 21 lbs but if someone chooses 4 day, the weight is 27 lbs.

I need an app that will do this for my customers during checkout. Ill set a few examples

• (Product)10lbs case of meat - (Destination) North California - (Transit Time) 2 Day Shipping - Add 2.5 lbs to base weight for Dry ice = "X" Amount
• (Product)10lbs case of meat - (Destination) South California - (Transit Time) 3 Day Shipping - Add 5 lbs to base weight for Dry ice = "X" Amount.

Thank you,

Angie