Buying an eSIM means guessing how many gigabytes you'll burn through. Guess low and you're topping up in a taxi queue; guess high and you've paid for data you never used. Put in how you actually use your phone and this works it out.
How the estimate works
Each activity is multiplied by a typical hourly data rate, then reduced by the share of time you expect to be on WiFi, then given a 15% buffer. These are planning figures, not measurements of your phone — app settings, video autoplay and background updates all move the real number.
| Activity | Rate used |
|---|---|
| Maps, messaging & browsing | ~60 MB/hr |
| Social media with video | ~500 MB/hr |
| Music streaming (standard quality) | ~70 MB/hr |
| Video, standard definition | ~1 GB/hr |
| Video, HD | ~3 GB/hr |
| Video calls | ~1 GB/hr |
| Laptop work over hotspot | ~150 MB/hr |
Video figures follow Netflix's published estimates (about 1 GB/hr SD, up to 3 GB/hr HD). Short-video apps can use more than the social media figure if you scroll video continuously.
Ways to use less data abroad
- Download offline maps for each city over WiFi before you head out.
- Download playlists, podcasts and shows at the hotel instead of streaming them on the go.
- Turn off video autoplay in social apps, and set app updates and photo backups to WiFi only.
- Use hotel and café WiFi for the heavy stuff — but with a VPN on, since shared networks are where snooping happens. See the best VPN for airport and hotel WiFi.
New to eSIMs? The eSIM guide for travelers covers how they work and how to set one up before you fly. Traveling for months? See the cheapest way to stay connected long-term.
Frequently asked questions
How much mobile data do I need for a week abroad?
For typical use (maps, messaging, some social media and browsing, no video streaming on mobile data), most travelers use roughly 0.5 to 1 GB per day, so 3 to 10 GB covers a week. Streaming video or making video calls on mobile data pushes that up quickly.
How much data does Google Maps use?
Navigation uses relatively little data, typically a few megabytes per hour. Downloading offline maps over WiFi before you go reduces it further.
How much data does streaming video use?
Netflix estimates about 1 GB per hour for standard definition and up to 3 GB per hour for HD. That makes streaming on mobile data the single biggest driver of how large an eSIM plan you need.
Should I buy a bigger eSIM plan than I think I need?
A buffer of 10 to 20 percent is sensible. Most eSIM apps, including Saily, let you top up if you run low, so there is little reason to buy far more than your estimate.