Unfortunately, I really don't have a good way to do that. It's about 3/8 of an inch across. I've never worked with ribbon yarn, either - these were given to me to do what I wanted.
I need to know what shipping would be to 73533. You could put them on your house scales to weigh them. If you need to put them in a container to keep them on the scales, weigh the container and then the yarn in the container and subtract it from the container weight.
The yarn is not immediately accessible - I live in a pet-filled house (my partner is a veterinarian), and I'm keeping the yarn in the trunk of my car so that the animal fur and dander don't get into it.