Will shipping quotes be accurate without dimensions?

[OB7DEV]

I've set up a Magento2 store using both UPS and USPS for shipping, it pulls prices based on the product weight and seems to be working well.

But I have a question, is there any way to also include the product dimensions when pulling the quotes?  My client is very picky and is telling me that he is 100% sure the shipping quotes will be off without passing the dimensions.  We are rebuilding his online store in Magento specifically due to the buggy nature of his current online store, and accurate shippings quotes are his number one priority for this new Magento site.

The quotes the Magento2 site is pulling now just using the weight seem pretty accurate.  But to satisfy my picky client I need to either explain to him why I don't need to pass the dimensions when getting quotes, or make him happy by passing the dimensions when pulling quotes. 

Anyone who can explain to me how or why we don't need the dimensions would be very helpful.

Thank you.

[Pronto · Accepted solution]

I suggest that you explain customer how averages work: you win some, you lose some, but when you set your price right you remain in black in the long run. Starting to chase cents by calculating exact prices based on weight and dimension will eventually only lead you to realm of total confusion: what happens if you purchase two items with weird proportions, can you put several items into single package? And so on and so on. When you find that calculations are wrong for some reason, what then? Ask extra fee for delivery? How much time does it get to get dimensions for all products? With packaging or without?

[OB7DEV]

Thank you, I now can explain to the client why we only need weight.  This makes sense.  Thank you.