eSIM data usage calculator

For a typical week of maps, messaging, some social and light browsing, the calculator usually lands around 3–5 GB before you round up to a plan. Heavy streaming or hotspotting a laptop pushes you toward 10 GB or unlimited. Japan prices and networks are in our Japan eSIM guide.

For most travellers on a one- to two-week trip who use hotel or café Wi‑Fi for video, 10 GB is a comfortable default. It is tight if you stream HD video or hotspot a laptop for hours each day — run the calculator with a Heavy or Remote work preset to check.

It depends on what the other device does. Light email and browsing might add a few hundred MB an hour; a video call or software update can burn through gigabytes. The calculator’s hotspot slider uses 300 MB per hour as a planning mid-point for mixed laptop use — turn it up if you expect heavy transfers.

Video-heavy feeds are the main variable. We plan social scrolling at about 250 MB per hour (midway in the 100–300 MB/hr range commonly cited for Instagram/TikTok-style feeds). An hour a day for a week is roughly 1.7 GB before the buffer.

Often yes. Many “unlimited” travel eSIMs slow you down after a daily high-speed allowance, and hotspot rules vary. Always read the plan page. Our destination guides note what each provider publishes about fair use and hotspotting.

Yes, if you actually use it for the heavy stuff. Streaming, cloud backups, app updates and long video calls are the big savers. Maps and messaging still happen on the street, so the calculator only cuts the heavy activities when you tick hotel Wi‑Fi — it does not assume zero mobile use.

Most travel eSIMs are installed per phone. Set Devices / travellers to the number of phones that will each need their own plan, or hotspot from one phone if the plan allows it (and you accept the extra drain on that phone’s battery and allowance).

They are starting points for the sliders: Light is maps and messaging; Typical adds social and a little video; Heavy adds streaming; Remote work emphasises video calls and hotspot. Adjust any slider afterward — your URL updates so you can share the exact mix.