How many GB do I need for a trip?
With maps, messaging and some browsing, count on 1 GB per week. If you also watch video or share data, count on 5 GB for a week and 10 GB for two. Almost everyone overbuys because they estimate from their usage at home, where the phone sits on Wi-Fi all day and video goes unnoticed.
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The question is always asked with the same gesture: looking at a list of plans where the 20 GB one costs five euros more and thinking “just in case”. That “just in case” is why half of all travellers come home with two thirds of the plan unused.
What each thing uses
| Use | Approximate usage | In an hour |
|---|---|---|
| Google Maps navigating | about 5 MB per hour | 5 MB |
| WhatsApp: text, voice notes, the odd photo | about 10 MB a day | very little |
| Browsing and looking places up | about 20 MB per hour | 20 MB |
| Scrolling social media | about 100 MB per hour | 100 MB |
| Streaming music | about 100 MB per hour | 100 MB |
| Video at normal quality | about 700 MB per hour | 700 MB |
| Video calls | about 500 MB per hour | 500 MB |
Look at the first row and the last. One hour of video uses the same as a hundred and forty hours of navigating with Maps. The decision on how many GB to buy isn't made by the map: it's made by video.
Three profiles and their maths
| Profile | One week | Two weeks |
|---|---|---|
| Maps, messaging and looking places up | 1 GB | 2 – 3 GB |
| All that plus daily social media | 2 – 3 GB | 4 – 6 GB |
| Video, video calls or sharing data | 5 GB | 10 GB |
These figures assume you sleep somewhere with Wi-Fi and leave photos, backups and long video for the evening. If you're camping for two weeks, the maths is different.
How to find out your real usage
- Open your phone's mobile data settings and look at last month's usage.
- Subtract what you used at home on data instead of Wi-Fi, which is usually quite a lot.
- Divide by thirty to get your daily average and multiply it by the days of the trip.
- Add a twenty per cent margin and compare against that figure, not against the “just in case”.
And a practical rule: if you're torn between two plans and the difference is one euro, take the big one. If the difference is ten, take the small one. Falling short is fixed by buying another eSIM on the spot; overpaying isn't fixed at all.
How to use less without rationing
- Download the city's map before heading out: GPS works without data, what needs data is loading the map.
- Turn off automatic photo backup over mobile data. It's the most common silent leak.
- Lower video and music playback quality in each app's settings.
- Download music, series and podcast episodes on the accommodation's Wi-Fi.
- Check which apps update on their own and set them to Wi-Fi only.
How many GB for a week's trip?
With maps, messaging and searches, 1 GB is enough. If you also use social media daily, between 2 and 3 GB. If you're going to watch video or share data, count on 5 GB.
Does Google Maps use a lot?
Very little: about 5 MB per hour of navigation. A whole day walking around a city with the map open rarely goes past 100 MB.
What if I run out of data mid-trip?
You buy another eSIM and install it on the spot; there's nothing to wait for. That's why overbuying “just in case” doesn't pay.
Does sharing data with another phone use more?
It uses whatever that phone consumes, and it comes out of the same allowance. If you share with someone who watches video, count their entire usage as if it were yours.
Something off, or a price changed? Write to ayuda@zasesim.com and we'll fix it. Data when you land.