How much mobile data do you actually need abroad?
Real megabyte-per-hour figures for maps, messaging, social feeds and video — and why most travellers buy two or three times more data than they use.
onesim team
Most people buy too much travel data, and a few buy far too little. Both mistakes come from the same place: nobody has an intuition for what a megabyte is.
These are the figures our own calculator runs on. They are per hour of active use, except where noted.
What an hour actually costs
| What you are doing | Per hour | For context |
|---|---|---|
Maps and navigation | About 5 MB | Google Maps, Apple Maps |
Messaging, email, browsing | About 25 MB | WhatsApp, Gmail, Safari |
Music and podcasts | About 70 MB | Spotify at high quality |
Video calls | About 500 MB | FaceTime about 400 MB, WhatsApp video about 300 MB |
Social feeds | About 500 MB | Instagram about 500 MB, TikTok about 840 MB |
Video streaming | About 900 MB | YouTube at 480p about 560 MB, Netflix standard about 1 GB |
Two more that are measured per day rather than per hour: photo and video backup is about 90 MB a day for roughly 25 photos and a short clip, and background app activity — notifications, weather, silent syncing — is about 30 MB a day even when you are not touching the phone.
The pattern is obvious once you see it in one table. Navigation is nearly free. Video is not. An entire week of walking around a city with the map open costs less data than twenty minutes of TikTok.
So what does a week cost?
For most travellers, 3 to 5 GB covers a week of maps, messaging, some browsing and a bit of scrolling. If you stream video or make a daily video call home, plan for 8 to 10 GB for the same week.
Here is the arithmetic behind those numbers for a normal day:
- 90 minutes of maps: 8 MB
- 2 hours of messaging and browsing: 50 MB
- 30 minutes of scrolling: 250 MB
- Photo backup: 90 MB
- Background: 30 MB
That is about 430 MB a day, or 3 GB a week. Add an hour of video an evening and the same week is over 9 GB.
The two mistakes
Buying for the worst day. People imagine the day their flight is cancelled and they spend three hours on hold with a video call open. That day almost never happens, and when it does you can buy another package in two minutes from your phone.
Buying for a habit you will not have. The reason you use less data on holiday is that you are outside, walking around, looking at things. The evening scroll happens on the hotel Wi-Fi.
Four travellers, four numbers
The same city, the same week, four different bills.
| Traveller | Daily habit | A week |
|---|---|---|
The navigator | Maps, messages, a few searches, photo backup on hotel Wi-Fi | About 1.5 GB |
The normal one | The above plus half an hour of scrolling and some music | About 3 GB |
The sharer | The above plus stories, video calls home and photo backup on mobile data | About 7 GB |
The one with a laptop | All of it, plus tethering for work in the evenings | 10 GB and up |
Two things move the number more than anything else. Tethering a laptop is the big one: a laptop treats the connection as home broadband and will download a system update over it if you let it. And photo backup left on mobile data quietly doubles a light user's week.
Both are one setting each, and both are in twelve settings that stop your phone eating data abroad.
How to know your own number
Your phone has been counting the whole time.
- iPhone: Settings → Mobile Data (or Cellular) → scroll to the bottom → Reset Statistics. Reset it at the start of a normal week at home and look at it seven days later.
- Android: Settings → Network & internet → Internet → the gear beside your carrier → Data usage. Most versions show a 30-day graph and the top apps.
Do it once and you never have to guess again. The number will be higher than your travel number, because at home you are not sitting on Wi-Fi in a hotel every evening.
If you would rather answer questions than do arithmetic, our data usage calculator turns your trip length, destinations and habits into a figure, and shows the packages that cover it.
What happens when you run out
With a prepaid travel package, your data stops. It does not roll on at a roaming rate and it does not generate a bill — you buy another package from the website or the app and it attaches to the same eSIM, so there is nothing to install again.
That is the practical argument for buying the smaller package: the downside of being wrong is two minutes and a few euros, not a surprise on next month's bill.
