Printed books versus e-readers
Printed books have an ongoing footprint from paper production, printing, and shipping for every single book. An e-reader has a large one-time manufacturing footprint (materials, electronics, battery), but a very small footprint per additional book downloaded, since it reuses the same device.
How the comparison works
This calculator multiplies your books-per-year by your e-reader’s lifespan to get a total book count, then compares the total footprint of buying that many physical books against the e-reader’s one-time manufacturing footprint plus a small per-download footprint. It also calculates the break-even point: the number of books at which the e-reader’s upfront footprint has been fully offset by avoided physical-book emissions.
Default figures are widely-cited approximations from lifecycle studies; actual numbers vary by book size, print run, shipping distance, device model, and how long you keep the e-reader. Buying used books, sharing books, or borrowing from a library also reduces the physical-book footprint substantially and isn’t captured here.