The most common mistake
The two most common mistakes when choosing a travel data plan are opposite problems: buying far more data than you will ever use, or badly underestimating and running out on day four of a ten-day trip. Both are avoidable with a rough idea of what your actual habits use.
Typical daily usage by activity
Maps and navigation: minimal if you download offline maps before travelling (a five-minute task in Google Maps or Apple Maps). Live navigation without offline maps downloaded uses noticeably more.
Messaging apps (WhatsApp, iMessage): very low — text messages use almost no data, and even photo/video sharing is modest compared to other activities.
Social media browsing: moderate — an hour of scrolling Instagram or TikTok can use 200-500MB depending on how much video content you view.
Video calls: significant — a 30-minute video call can use 200-300MB, adding up quickly if you are calling home daily.
Streaming video (Netflix, YouTube): the heaviest use by far — an hour of standard-definition streaming uses roughly 1GB, with HD using considerably more.
A simple rule of thumb
For a typical trip mixing maps, messaging and some social browsing but minimal streaming, budget around 500MB-1GB per day. A week-long trip on that basis needs roughly 3.5-7GB total. If you know you will be streaming or making regular video calls, at least double that estimate.
Download before you fly
Whatever plan you choose, downloading offline maps and any content you might want to watch (via Netflix's download feature, for example) before you leave the UK meaningfully reduces your data needs once you land — worth doing regardless of which data plan you end up buying.
Compare travel SIM and eSIM data plans →