How Much Data Do I Need for Travel? Here's the Math
4 min read
One site tells you 0.5 GB a day is plenty. The next one budgets 2 GB, and the provider sitting between them would rather sell you 20 GB. No wonder nobody can answer the simple question: how much data do I need for travel? The arithmetic isn't complicated. Hours per activity, times the usage rate for that activity, times your trip length.
What actually burns data, per hour
| Activity | Data per hour |
|---|---|
| Navigation, no satellite view | 2 to 5 MB |
| Navigation with satellite map | 30 to 60 MB |
| Instagram feed, browsing | around 220 MB |
| TikTok, Reels | around 840 MB |
| Video call on WhatsApp or FaceTime | 150 to 300 MB |
| Zoom in HD | 780 MB to 1.2 GB |
| Netflix, depending on quality | 250 MB to 1 GB |
Maps? Basically free. Turn-by-turn navigation without satellite view runs on 2 to 5 MB an hour, according to Vodafone Germany. The line item almost everyone underestimates is the video call home: an HD Zoom call pulls up to 1.2 GB an hour per Vodafone's own figures. Netflix runs about 250 MB to 1 GB an hour depending on the quality setting, according to teltarif. Those are European carrier figures, but bitrate is bitrate, so they travel fine.
Worked example: 5 days in a city
A normal travel day, roughly. Half an hour of navigation, call it 2 MB. An hour of feed and reels mixed, 400 to 500 MB. One video call home, 150 to 250 MB. Half an episode before bed, 250 to 500 MB.
That totals about 1 to 1.2 GB a day. Five days, so 5 to 6 GB.
Without the evening streaming you'll probably land at half that. Tethering a laptop pushes it to double.
Two mistakes that wreck the estimate
Background traffic. Photo backups, app updates and Apple's Wi-Fi Assist keep running without telling you. Nomad eSIM calls this the most frequent culprit behind data that vanishes overnight.
Hotspot use. A laptop connected to your phone starts pulling its own updates and cloud syncs over your travel plan. Roamless reckons two connected devices simply double the usage.
Honestly, this is why I wouldn't optimise to the second decimal. My rule of thumb is whatever you calculated, plus 50 percent. Running out mid-trip costs a lot more than the spare gigabyte ever did.
That leaves the plan itself: eSIM for Thailand, eSIM for the USA or eSIM for Japan.
Frequently Asked Questions
How much data do I need for a week away?
Around 7 GB at moderate use, so 1 GB a day. If you mostly stick to maps and messaging, 3 to 4 GB covers it. If you stream in the evenings, 10 to 15 GB is the safer budget.
Do video calls use a lot of data?
More than most people expect. WhatsApp video sits around 240 to 300 MB an hour. Zoom in HD reaches 780 MB to 1.2 GB, which beats some streaming services outright.
What uses data in the background without me noticing?
Automatic cloud photo backups, app and OS updates, and background app refresh. On iPhones there's also Wi-Fi Assist, which quietly switches to mobile data when the signal gets weak.
Is 1 GB a day enough while travelling?
For most city trips, yes. Navigation, messaging, social and a short video call fit inside it comfortably. It gets tight the moment you stream in HD regularly or share the connection with a laptop.
