What page are you on?
Have you ever wanted to refer to a Kindle book by page number? Maybe you want to set your status on goodreads.com or maybe you want to generate an MLA or APA style reference for a paper. All the Kindle tells you is what "section" you are on. Even worse, those sections change based on the device's page size and your selected font.
To overcome this issue, I have created a very rough calculator to equate your Kindle position with a real page number. The reason I say rough is because the printed edition may not have the exact same content or layout as the Kindle edition. If you can accept these inherent limitations, you may find this tool useful.
My basic math is as follows: (Kindle position / Total Kindle sections) * number of pages in printed edition