How much data do I need for a Switzerland trip?

For a typical 5 to 7-day Switzerland trip covering Zurich, Lucerne, and Interlaken, 5 GB to 10 GB is enough for most travelers. A 10 to 14-day trip adding the Alps, Zermatt, and Geneva with daily SBB navigation, Google Maps, photo uploads, and WhatsApp usually needs 10 GB to 20 GB. Heavy users uploading content from mountain viewpoints or working remotely from Zurich cafés should pick the 25 GB or unlimited plan. SBB train apps and Google Maps consume less data than expected, but mountain photo uploads add up quickly.