HelloRoam bills in 31 checkout currencies while Airalo, Holafly, Nomad and Saily bill in US dollars only. This calculator averages the published hourly band of every app you pick, multiplies it by your hours on cellular data and your trip length, and returns a GB figure with a tier. Airalo reaches 200+ destinations to HelloRoam's 186.
·By MyeSIMPlan Advisors·Prices verified August 2026
Step 1
Tap the apps that will be part of your trip. The more data-hungry ones move the needle most.
Step 2
Time spent on mobile data, not counting hotel or cafe Wi-Fi.
Step 3
The biggest variable in your eSIM plan size is not your destination; it is your app habits. Maps run 5 to 50 MB per hour and messaging runs 1 to 30 MB per hour, which is close to free on any plan. Social feeds run 30 to 500 MB per hour, depending on how much of the feed is video. Streaming and video calls are the heavy hitters: 300 MB to 3 GB per hour for video, and 700 MB to 2 GB per hour for a call.
The calculator above averages the middle of each selected app's band, multiplies by the hours you spend on cellular data each day, and projects across your trip length. The result is a planning estimate, not a guarantee. Where you land inside a band depends on video quality settings, signal strength, and how often you connect to Wi-Fi at hotels and cafes.
If your estimate falls near the boundary between two tiers, choose the larger one. Running out of data mid-trip is a worse experience than having a gigabyte left over. Most providers let you top up instantly from their app, but the per-GB cost of a top-up is usually higher than buying the right size upfront.
Unlimited plans from Holafly ($2.99/day) make economic sense when your estimate exceeds about 7-10 GB for a week. At that point, the daily rate costs less than stacking large per-gigabyte bundles, and you gain the peace of mind of never counting data. Remote workers, streamers, and frequent video-callers almost always belong on unlimited.
