How much mobile data do you actually need abroad?
What a week of maps, messaging and photos really costs in gigabytes, what pushes it up, and how to pick a plan size you will not overpay for. With a table by trip length and by how you travel.
The short answer
For most travellers, 1 GB per week covers maps, messaging, email and light browsing. Add photo backup and social media and a week runs closer to 3 GB. Streaming video, video calls or tethering a laptop is what turns a fortnight into 20 GB or more. Buy the smallest plan that covers the trip: unused data is not refunded and does not roll over, and topping up mid-trip takes under a minute.
What each thing costs, roughly
These are working estimates, not guarantees — the same app moves very different amounts depending on video quality, how often it refreshes and whether it decides to back something up. They are close enough to size a plan with.
| Activity | Roughly | In an hour |
|---|---|---|
| Maps and navigation | 3–5 MB per hour of driving | ~5 MB |
| WhatsApp, iMessage, Telegram (text) | Under 1 MB per hour | ~1 MB |
| Email and light browsing | 10–20 MB per hour | ~15 MB |
| Instagram or TikTok scrolling | 100–250 MB per hour | ~150 MB |
| Photo backup to iCloud or Google Photos | 2–4 MB per photo | varies |
| Music streaming | 40–80 MB per hour | ~60 MB |
| Video call | 400–800 MB per hour | ~600 MB |
| Netflix or YouTube at normal quality | 0.7–3 GB per hour | ~1.5 GB |
By trip length and by how you travel
| Trip | Light: maps, messaging, email | Normal: plus social and photos | Heavy: video, calls, tethering |
|---|---|---|---|
| Weekend, 3 days | 0.5 GB | 1–2 GB | 5 GB |
| One week | 1 GB | 3–5 GB | 10–20 GB |
| Two weeks | 2 GB | 5–10 GB | 20–50 GB |
| One month | 3–5 GB | 10–20 GB | 50 GB or unlimited |
Two things move a traveller from one column to the next more than anything else. The first is whether photo and video backup is left on over cellular. The second is whether a laptop is tethered — a laptop treats the connection as home broadband and will download an operating system update over it without asking.
Why buying small is usually right
Larger plans always cost less per gigabyte, which makes the big one look like the sensible purchase. It is only sensible if you use it. Unused data is not refunded, does not roll over to a later trip and cannot be moved to another person, so the per-gigabyte price of data you never touch is infinite.
The asymmetry runs the other way too. Running out mid-trip used to mean buying and installing a second eSIM; on any plan sold here you add data to the eSIM already in the phone, without a new QR code and without reinstalling anything. Underbuying costs you a minute. Overbuying costs you the difference.
How to use less, if you want to
- Turn off photo and video backup over cellular. On iPhone: Settings › Photos › Mobile Data. On Android: the Google Photos app › Settings › Back up › Mobile data usage.
- Download maps for the area before you fly. Google Maps and Apple Maps both do this, and offline maps still navigate with GPS, which uses no data at all.
- Download the playlists, podcasts and episodes you want on hotel wifi rather than streaming them on the move.
- Set video apps to a lower quality. The difference between "auto" and "data saver" on YouTube is roughly threefold.
- Watch the counter. iPhone: Settings › Mobile Service, and reset the statistics for the travel line when you land. Android: Settings › Network & internet › SIMs › Data usage.
Common questions
- Is 5 GB enough for a week abroad?
- For most people, comfortably. Five gigabytes covers a week of maps, messaging, email, browsing and a normal amount of social media. It is not enough for a week of streaming video, daily video calls or tethering a laptop.
- Does using maps abroad use a lot of data?
- No. Navigation is one of the cheapest things a phone does — roughly 3 to 5 MB an hour of driving, because GPS itself uses no data and only the map tiles are downloaded. Downloading the area for offline use before you travel reduces it to almost nothing.
- What happens when a travel eSIM runs out of data?
- It stops carrying data. It does not charge you more, and it cannot bill you again — a prepaid eSIM has no way to overspend. You add data to the same eSIM in the phone, which takes under a minute and needs no new QR code and no reinstallation.
- Does unused data on a travel eSIM roll over?
- No. Data that goes unused expires with the plan, is not refunded and cannot be moved to a later trip or another person. That is why the smallest plan that covers the trip is usually the right one.
Written by Ahoray · Last revised 6 September 2026
The other guides
Travel eSIM or your carrier’s roaming: which is actually cheaper?
A day pass charges by the day, an eSIM by the gigabyte — which is cheaper depends entirely on the shape of your trip.
Does my phone support eSIM? How to check in ten seconds
Dial *#06#: if an EID number appears the phone supports eSIM. It must also be carrier-unlocked, which is a separate thing.
eSIM installed but no service: what to check, in order
Almost always data roaming, or the wrong line selected for data. Whatever you do, do not delete the profile.
How to choose a travel eSIM: the six things that actually differ
Price per gigabyte, exit-IP country, tethering rights and top-ups — the coverage map is the least useful comparison.
Does a travel eSIM give you a phone number? (WhatsApp, SMS and bank codes)
None of them have a number, so SMS codes arrive on your own line. WhatsApp and iMessage work normally over the data.
