"How much data do I need?" is the question we get asked most, and the honest answer is that it depends entirely on how you use your phone. So instead of a vague answer, here are the actual numbers per app, three traveller profiles, and the plan size that fits each one.
These figures come from Roamly's own usage data across more than a terabyte of customer traffic, plus published app benchmarks. They're averages. Your mileage will vary, but not by as much as you'd think.
Data use per app, per hour
Google Maps navigation: 5MB to 10MB. Tiny, unless you're loading satellite view.
WhatsApp and iMessage: negligible for text. Photos are 1MB to 3MB each.
WhatsApp or FaceTime voice call: 30MB to 50MB.
WhatsApp or FaceTime video call: 300MB to 500MB.
Instagram, scrolling and Reels: 100MB to 200MB.
TikTok: 500MB to 800MB. It's the hungriest app most people carry.
Spotify or Apple Music streaming: 40MB to 100MB depending on quality. Download playlists before you fly.
YouTube at 720p: 700MB to 1GB.
Netflix at standard definition: about 1GB. High definition is 3GB.
Web browsing and email: 30MB to 60MB.
Grab, Uber, Gojek: negligible per ride, maybe 5MB.
Google Translate camera mode: 20MB to 40MB. Download the language pack for offline use.
Hotspotting a laptop for work: 500MB to 1GB, and much more if you're on video calls.
Three types of traveller
The light user
Maps to get around, WhatsApp to stay in touch, a bit of browsing, and photos uploaded on hotel Wi-Fi at night. Maybe one video call home a week.
Daily use: 200MB to 400MB. Two weeks: 3GB to 5GB.
A 5GB plan is comfortable. A 3GB plan works if you're disciplined about Wi-Fi.
The normal user
Everything above, plus Instagram every day, Reels on the bus, a video call home every couple of days, Spotify on the beach, and Grab for getting around. This is most people.
Daily use: 600MB to 1.2GB. Two weeks: 8GB to 15GB.
10GB is the sweet spot. For a 30-day plan you'd want 20GB.
The heavy user
Working remotely with video meetings, streaming at night because the hotel Wi-Fi is bad, TikTok, uploading video content, or hotspotting a laptop and a partner's phone.
Daily use: 2GB or more. Two weeks: 20GB to 50GB.
Go for 20GB minimum, and pick a reloadable plan so you can top up rather than buying a second eSIM.
Four ways to use less without noticing
Download offline maps for each city in Google Maps before you go. Navigation then uses almost no data.
Turn off background app refresh for apps you don't need updating constantly. Instagram, Facebook and news apps are the usual culprits.
Set streaming apps to "data saver" or download playlists and episodes on Wi-Fi.
Enable Low Data Mode on iPhone or Data Saver on Android for the travel eSIM line. It stops automatic downloads and pauses iCloud photo sync until you're on Wi-Fi. Photo backup is the silent killer: one day of holiday photos can be 2GB.
What if you get it wrong?
Buying too little isn't a disaster. Roamly plans marked as reloadable can be topped up from the My eSIMs page without installing anything new, and your usage is shown live so you'll see it coming. Buying too much costs a few dollars. The gap between a 5GB and a 10GB plan is usually A$5 to A$8, which is less than one day of carrier roaming, so if you're on the fence, size up.
Browse plans by destination, or read what "unlimited" really means before you buy a plan that promises it.