When to use dimensions?

[lazer*lightning]

I usually sell small stuff that buyers pay the cheapest shipping on and don't bother to enter in dimensions. Today I found out that a 5 lb. 8 oz laptop I was short on charging an additional $3.84 for one that sold. Of course I can't charge him more money as it's my mistake but is it only worth it to add dimensions to just items sold over a pound and irregular shaped packages or all items if the buyer wants to pay for faster shipping methods?  

[midwestmerch17]

I use a rough estimate of the dimensions for just about every listing. I find it is worth the extra time to keep from under charging on shipping. 😀

[richard1rst]

When to use dimensions?

ALWAYS - well except for small things that can fit a padded envelope.

And EXACT dimensions (rounded to the next inch), not rough dimensions.

More and more the SIZE of the box determines the shipping more so than the weight. For the longest time UPS and FedEx have used size rather than weight.  USPS is now doing the same.

Are you familiar with Flat Rate Boxes?  The one draw back there was that there were only a few sizes available. But now with Cubic Box pricing the same concept applies to ANY box - even your own plain generic cardboard boxes.

For example, a 2 pound box measuring 8x8x2 costs less to ship than a 2 pound box measuring 8x8x8 which costs WAY less to ship than a 2 pound box measuring 14x14x14.

BUT here's  the wrinkle. A 5 pound box also measuring 8x8x2 costs the SAME to ship as the aforementioned 2 pound box. It is the SIZE not the weight.