What uses data
Rough figures for an hour of use. Apps vary, and video quality makes the biggest difference.
- Maps and directions: around 10–20 MB.
- Messaging: very little for text. Photos and voice notes add a few MB each.
- Web browsing: around 50–150 MB.
- Music streaming: around 50–150 MB.
- Short-video apps (TikTok, Reels, Shorts): around 0.5–1 GB.
- Video calls: around 0.5–1.5 GB.
- Streaming shows: around 1 GB in standard quality, 3 GB or more in HD.
Daily budgets
- Light, about 0.5 GB a day: maps, messages and some browsing, with Wi-Fi at the hotel.
- Typical, 1–2 GB a day: add social media, photo uploads and the odd video.
- Heavy, 3 GB or more a day: video calls, streaming, or sharing data with a laptop. An unlimited plan usually works out cheaper.
A worked example
A week in Japan with typical use: 7 days × 1.5 GB is about 10 GB. A light user would manage on 5 GB.
If you're between two sizes, pick the bigger one, or a provider that lets you top up the same eSIM. Running out halfway through a day of train connections is worse than paying a dollar or two more.
Fixed data or unlimited?
Fixed-data plans are cheaper when you know roughly what you'll use. Unlimited plans suit heavy users, but most slow down after a set amount each day, often 2–5 GB, to around 1 Mbps. That's enough for maps and messages, not for video. Check the daily limit and any hotspot limit before you buy.
Make your data last
- Download offline maps in Google Maps or Apple Maps before you go.
- Turn off automatic updates and photo backup over mobile data.
- Turn on Low Data Mode (iPhone) or Data Saver (Android).
- Download playlists and shows at home.
- Save big uploads for the hotel Wi-Fi.
Running low?
Many providers let you top up the same eSIM in their app. Otherwise, buy a second small plan. Either way, you don't need to change any settings beyond switching data to the new line.
Compare plans by destination to see what each size costs.