Below is a link to a paper savings calculator that Environmental Defense, a leading environmental organization, has created.
This is a great tool to use on projects to determine the environmental benefits of a specific paper with post-consumer content, versus its virgin fiber alternative. I prefer using this tool over other tools because it is a third-party resource, not affiliated with the paper/print/marketing industries. It’s transparent and backed by an organization that is not-for-profit focused on “tackling the most serious environmental problems.”
http://www.edf.org/papercalculator/

[...] I have written in the past about resources available to quantify such environmental savings. One great paper calculator is managed by Environmental Defense, a leading environmental organization. I prefer it over other alternatives because it is a third-party tool and is not affiliated with the paper industry. Research has shown that when certifications are independent and transparent, they resonate more with the end user. Please click here to visit that post. [...]