How much mobile data does a trip actually use?

Field numbers for maps, messaging, streaming, and hotspot work - and what a realistic two-week trip costs on PAYG vs day-pass roaming.

Every roaming product is priced against your uncertainty about one number: how many megabytes you'll actually use. Carriers sell $15/day passes because you can't estimate it; unlimited-plan eSIMs charge for a ceiling you'll never hit. Here are the real numbers, so you can do the math yourself.

What common activities cost in data

Google/Apple Maps navigation: 3–5 MB per hour of active navigation. A full day of walking-tour usage is under 30 MB.
Messaging (WhatsApp/Signal/Telegram): text is negligible; voice notes ~0.5 MB/min; photos 1–3 MB each as sent.
Voice calls over data (WhatsApp/FaceTime audio): ~0.5–1 MB per minute. An hour of calls is well under 100 MB.
Video calls: 5–15 MB per minute depending on quality. This is the one that quietly eats budgets.
Social feeds (Instagram/TikTok): 100–200 MB per hour of scrolling - autoplay video is the culprit.
Music streaming: ~50 MB per hour at normal quality; half that with data-saver on.
Video streaming: ~700 MB per hour at 480p, ~1.5 GB at 1080p, ~3 GB at 4K.
Laptop hotspot for email/docs/Slack: 100–300 MB per working hour; add video meetings and it jumps to 500 MB+.

Three realistic traveler profiles

Light (maps + messages + a little social): 200–400 MB/day → roughly 4 GB for two weeks. On Anon eSIM in Western Europe (~$0.80–0.90/GB) that's about $3.50 total. One day of a $15 carrier day pass costs more than the entire trip.

Moderate (the above + an hour of social video + music + occasional video call): 700 MB–1 GB/day → roughly 12 GB for two weeks. That's $10–11 in Europe, ~$17 in the US ($1.40/GB), ~$8.50 in Thailand ($0.70/GB).

Heavy (remote work over hotspot + evening streaming): 2–3 GB/day → 30–40 GB for two weeks. Even this worst case is $25–35 in Europe on PAYG - still under three days of day-pass fees, and it's the one profile where "unlimited" plans are worth comparing (check their tethering caps first; most cap hotspot at 0.5–1 GB/day, which kills the remote-work use case anyway).

The two habits that actually save data

Forget micro-optimizing. Two settings cover 90% of waste: download offline maps and playlists on hotel Wi-Fi, and disable autoplay/background app refresh for social apps. iOS Low Data Mode and Android Data Saver do most of this in one toggle, per SIM.

Why this favors pay-as-you-go

Priced per GB, the uncertainty stops mattering. A light week costs cents; a heavy week costs what it costs, visible in real time on your balance - and on published per-country rates there's no cliff at day 15 and nothing expires. Day passes and unlimited bundles are insurance products; once you know your number, you stop needing the insurance.