I have carefully researched your question and have your answer.
Some of the types of English walnut include: Hansen, Perry,
Shiawassee, Fairview, Sommers, Looking Glass, S-1 Walnut, and China-B.
Depending on the type of English walnut, the nut meat to whole walnut
weight ratio ranges from 50 percent to 65 percent. Therefore, if you
shell 20 pounds of English walnuts, you'll have about 10-13 lbs. of
The best web site I found that discusses the weights of different
English walnuts was the Grinnell Nursery site. The link is
There are various factors involved with how much a walnut weighs. This
study has been done: http://www.actahort.org/books/544/544_35.htm
The nut meat weight also is correlated with the size of the nut. A
good link is http://www.actahort.org/books/544/544_17.htm
To conduct this research, I searched the following terms: walnut nut
weight, "english walnut," walnut weight.
I hope this helps. If you need any clarification, please don't
hesitate to ask.