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+ |
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.
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.
- 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.