Caliber (Windows / Mac / Linux)
If you want to convert your ebooks in a "traditional" way, ie using a desktop application, I recommend using Caliber. Caliber is an excellent free, open source and multi-platform software (i.e. compatible with Windows, Mac OS X and Linux) that allows you to view, manage and convert ebooks of any kind.
To download it on your computer, connected to its website, select the logo of the operating system installed on your PC (eg the Windows flag or the Mac OS X apple) and click on the item Download Caliber found on the page that opens.
When the download is complete, if you are using a Windows PC, open the software installation package (caliber – xx.exe), put the check mark next to the item I accept the terms in the License Agreement and click in sequence on install, Yes e Finish to conclude the setup. If, on the other hand, you are using a Mac, open the dmg package you downloaded from the Caliber site, select the software icon present in the latter and drag it to the folder Applications in OS X.
At this point, start Caliber and go through the initial configuration procedure of the program, during which you will have to indicate the folder in which to save the library and, if you have it, the tablet or ebook reader model to which to transfer the books. Next, click on the button Add books located at the top left and select all the ePub files to convert.
Then wait for the ebooks to be added to the Caliber library, select them with the mouse, click on the button Convert books (located at the top left) to access the conversion settings screen and choose the option PDF from the drop-down menu located at the top right.
Now you have to change the margins of the pages and the writing font of the ebook so that they are suitable for the PDF file format (otherwise you would get documents with huge writings poorly paged). Then select the wording PDF output from the left sidebar, put the check mark next to the item Ignore the paper size set in the output profile and set the menu Sheet size su Letter and the field Default font size su 14 (or a slightly higher or lower value).
Next, move to the section Set page, rule all margini page to a value of 50 and click on OK to start converting your ebooks. When the operation is completed, you can view the PDFs obtained by selecting the title of a book from the Caliber library and clicking on the item Click to open located on the right.
ToPDF (Online)
It is possible too convert ePub files to PDF online, directly from the browser. How? For example by turning to a service like ToPDF that allows you to transform many different types of digital documents, including ePubs, into PDFs. It's completely free, requires no registration, and supports simultaneous conversion of up to 20 files. It also protects the privacy of us users by deleting all data that is uploaded to its servers within a few hours.
To use it, connect to its home page and drag the ebooks to convert to PDF in the center of the screen (where it says Drop your files here). Therefore, wait for the conversion to complete and choose whether to download the individual files by clicking on their thumbnails or to download a zip package containing all the ebooks you have converted by clicking on the button Download zip. Easier than that?
How to convert ePub files to PDF