It depends on how you use your phone, but here are general guidelines:
- Light use (maps, search, messaging): around 0.3–0.5GB per day
- Typical use (plus browsing social media and posting photos): around 0.5–1GB per day
- Heavy use (video streaming, video calls, tethering): 1.5GB or more per day
For a 5-day trip using mostly maps and social media, roughly 3–5GB is a reasonable starting point.
Ways to use less: stream video and update apps on hotel Wi-Fi, save maps offline, and turn off video autoplay (more tips).
When in doubt, start smaller: you can top up anytime, so adding data when you need it wastes less — and note that unused data expires with the plan.