Most travellers overbuy. Here’s how to size a plan without guessing.
The quick formula
Daily need (GB) × trip days × 1.3 buffer = plan size
Round up to the nearest plan the provider sells. The 1.3 buffer covers the days you use more than expected (travel days, getting lost, sharing your hotspot).
Daily need by usage style
| Usage style | What that looks like | Per day |
|---|---|---|
| Light | Maps, messaging, ride-hailing, occasional email, a few photos to family | 0.2–0.4 GB |
| Normal | The above plus social scrolling, some music, web browsing, a short video call | 0.5–0.8 GB |
| Heavy | Streaming music/video daily, lots of Reels/TikTok, uploading photos and video, video calls | 1–2 GB |
| Tethering | Using the eSIM as your laptop’s main connection for work | 2–5 GB+ |
What common activities actually cost
Useful when you want to sanity-check the table above against your own habits, rather than just picking a category:
| Activity | Typical data use |
|---|---|
| Google/Apple Maps navigation | ~5–10 MB per hour of active turn-by-turn |
| Music streaming (Spotify, normal quality) | ~40–70 MB per hour |
| Video call (WhatsApp/FaceTime) | ~200–300 MB per hour |
| Standard-definition video streaming | ~700 MB–1 GB per hour |
| HD video streaming | ~1.5–3 GB per hour |
| Scrolling Instagram/TikTok | ~150–300 MB per hour, more if autoplay video is high quality |
| Sending a handful of photos | ~5–20 MB per photo, depending on camera resolution |
| General web browsing and messaging | ~40–100 MB per hour |
Turning off autoplay video and capping streaming quality to “data saver” in each app’s settings can meaningfully cut the heavy-use numbers above.
Worked examples
- Weekend in a city, normal use: 0.7 GB × 3 days × 1.3 ≈ 3 GB.
- Two weeks in Southeast Asia, normal use: 0.7 × 14 × 1.3 ≈ 13 GB → buy a 15–20GB plan (data is cheap there anyway).
- 10 days in Europe, light use: 0.3 × 10 × 1.3 ≈ 4 GB → a 5GB plan.
- A month abroad working from a laptop: 3 GB × 30 ≈ 90 GB → this is where a Holafly-style unlimited plan or a local physical SIM usually beats buckets.
- A week-long business trip, mostly email and video calls, no streaming: 0.6 GB × 7 × 1.3 ≈ 5.5 GB → a 6–8GB plan, sized up slightly if the video calls run long.
- Family trip with two kids on tablets: treat each device separately if they’re not all on one hotspot — a tablet streaming cartoons for a few hours a day can use as much data as an adult’s whole day of normal use.
When unlimited makes sense
Unlimited-by-days plans (Holafly) are priced so that they only win if you’d otherwise buy a large bucket. As a rough line: if your maths says 20GB or more, price the unlimited option too. Below that, buckets are cheaper. Watch for daily high-speed caps and hotspot limits on unlimited plans.
Don’t forget
- You can usually top up mid-trip (Airalo, Saily, Nomad, aloSIM) if you run low — so buying slightly under and topping up is a valid strategy. It’s also the safer direction to round when you’re unsure, since a slightly-too-small plan costs you a top-up, while a too-large plan is money you can’t get back.
- Download offline maps (Google Maps / Organic Maps) and offline Spotify/Netflix before you go. This alone can halve a normal user’s data.
- Hotel and café Wi‑Fi still exists — your eSIM is for when you’re moving around.
- If you’re travelling with someone, check whether your plan supports hotspot/tethering to a second device before assuming you can split one plan two ways — some providers restrict or throttle this.
FAQ
Does using an eSIM instead of Wi‑Fi calling use more data? No — Wi‑Fi calling uses your Wi‑Fi connection, not the eSIM, whenever Wi‑Fi is available. The eSIM only carries traffic when you’re off Wi‑Fi.
Will video calls over the eSIM eat my data faster than a normal call? Yes, substantially — a video call runs 200–300MB per hour versus a few MB for a voice-only call over data. If you’re tight on data, switch the camera off for calls that don’t need it.
Do unused GB roll over if I buy another plan from the same provider? Almost never — travel eSIM data typically expires with the plan’s validity window, whether or not you used it all. Size down slightly and top up rather than buying a big buffer “just in case.”
See the country-by-country tables on this site for current unlimited and capped-data prices, or start with what an eSIM actually is if you’re new to this.