It’s the first Monday of October, aka National Consignment Day: the official holiday that celebrates the positive impact consigning has on the environment. Last year we celebrated by announcing our sustainable partnership with Stella McCartney (an initiative that’s still going strong), and this year we also have big news: the unveiling of a first-of-its-kind sustainability calculator. It was developed specifically for us with the help of environmental consulting firm Shift Advantage and overseen by six sustainable textile industry experts including Eliot Metzger of the World Resources Institute, Camille Gillet of the Ellen MacArthur Foundation and Sustainability Consultant Michael Sadowski. For its first computation, we used the calculator to determine the water, energy and greenhouse gas savings from the most popular women’s clothing items (dresses, tops, jackets and knitwear) consigned on The RealReal since January 2012. And the results are big. Scroll through above to see how much was saved and the unique methodology we used to figure it out.