When you start using an eSIM while traveling, one of the first questions is usually, "How many gigabytes should I buy?" The short answer: for typical use centered on maps, social media, and messaging apps, a good rule of thumb is 0.5–1GB per day. For a short 3–4 day trip, that's around 3GB; for a week, roughly 5–10GB; and if you'll be away for two weeks or more or watch a lot of video, an unlimited plan becomes worth considering. In this guide, we'll lay out data estimates by trip length and usage style in easy-to-read tables, and walk you through how to think about it when you're not sure an amount will be enough — written so first-time users can follow along. If you're stuck on capacity, it also helps to line up and compare the plans for your destination on our eSIM comparison page.
- Your data needs come down to "days of use × how you use it"
- For typical use, plan on about 0.5–1GB per day
- Roughly 3GB for 3–4 days, and 5–10GB for a week
- For heavy video, tethering, or long stays, unlimited gives peace of mind
- Phone calls and SMS via a number aren't supported, but app-based calls (e.g. WhatsApp) work
The bottom line: it comes down to "days × how you use it"
Choosing an eSIM's data size doesn't need to be complicated. Really, it comes down to just two things:
- How many days you'll use it
- How much you use each day (light / typical / heavy)
Multiply those two together and you get a rough idea of the GB you'll need. To give you the big picture first, we'll go through a per-day estimate by usage type, then a total estimate by number of days. Keep in mind that the amount you actually need varies with how you use your apps and how many photos and videos you share, so treat these as estimates and choose with a little room to spare. If you'd like to jump straight to a plan that fits, you may also find our eSIM guide collection helpful.
What uses data, and how much? Estimates by activity
Knowing roughly how much data common activities use makes it much easier to picture what you'll need. The table below shows general estimates; actual figures shift with video quality, settings, and network conditions.
| Activity | Approximate data used |
|---|---|
| Maps & navigation (1 hour) | About 5–10MB |
| Messaging apps, back-and-forth chat (1 day) | About 10–30MB |
| Web search & reading news (1 hour) | About 10–30MB |
| Browsing social media (1 hour) | About 100–300MB |
| Music streaming (1 hour) | About 50–100MB |
| Watching video, standard quality (1 hour) | About 300–700MB |
| Video calls (1 hour) | About 300–600MB |
The key takeaway: maps, messaging, and search use surprisingly little data, while playing videos in your social feed, watching video, or making video calls eats through it much faster. Picturing what you'll use most while traveling makes it far easier to estimate the capacity you need.
Data estimates by number of days
Here are rough total estimates by length of stay. "Light" centers on maps, search, and messaging; "typical" adds in browsing social media for everyday use; and "heavy" means you also use video and video calls regularly.
| Length of stay | Light | Typical | Heavy |
|---|---|---|---|
| 1–2 days | 1GB | 2–3GB | Around 5GB |
| 3–4 days | 2–3GB | 3–5GB | Around 8GB |
| 5–7 days | 3–5GB | 5–10GB | 10GB+ / unlimited |
| 8–14 days | 5–8GB | 10–15GB | Unlimited for peace of mind |
| 15+ days / long stay | Around 10GB | 15GB+ | Unlimited worth considering |
The longer you stay, the more total data you'll need, and the more heavily you use it each day, the more an unlimited plan is worth a look. If your trip is short and your usage is light, a small-capacity plan is often more than enough.
How to choose by usage type
Numbers alone can be hard to act on, so here's a way to think about it by type of user.
The budget-conscious, stay-in-touch type
Mostly maps, messaging, and the occasional search. Even about 0.5GB a day is often enough, and for short trips a small-capacity plan keeps costs down.
The typical traveler who wants to enjoy the trip
Posting photos to social media, looking things up — everyday use. Plan on about 1GB a day and choose based on your number of days for a good balance.
The video-and-tethering power user
You watch video on the go, or connect a laptop or tablet (tethering). Since this uses a lot of data, a large-capacity or unlimited plan gives peace of mind. Note that whether tethering is allowed, and under what conditions, can differ from plan to plan, so please check before you buy.
How to think about it when you're not sure it's enough
Worrying about whether an amount will be "just enough" is especially common for first-timers. Here are three ways to approach it.
1. Choose with a little room to spare
Picking one size up from exactly what you think you need gives you peace of mind. While traveling, you tend to use maps and look things up more often than expected.
2. Use Wi-Fi alongside it
When you connect to Wi-Fi at your hotel or a café, you're not using your eSIM data during that time. Doing video and app updates over Wi-Fi helps conserve your data.
3. Consider unlimited if you use a lot or can't predict it
If your stay is long, you watch video every day, or you simply don't want to think about how much is left, an unlimited plan is worth considering. Just keep in mind that "unlimited" doesn't mean "completely without any conditions."
What to know before choosing an unlimited plan
Unlimited plans suit people who want to use data without watching the meter, but they commonly come with conditions like these:
- A fair-use policy (speeds may be reduced after a certain amount of heavy use)
- Whether tethering is allowed, and any data conditions, vary by plan
- Speeds depend on the local network, area, and congestion at different times of day
These reflect how most unlimited eSIMs work, and "unlimited" doesn't always mean "full speed no matter how much you use." It's convenient for long sessions and heavy use, while checking these conditions in advance helps you avoid surprises once you're there. For how unlimited fits in and what conditions apply, please see the latest details on our guide to unlimited eSIMs and the unlimited plan page.
If you run low on data
If your balance does run low during your stay, there's no need to panic. With Bloomy, you can top up data on the eSIM you're already using. Instead of buying a whole new plan, you can add capacity to the same eSIM and keep going.
We also offer auto-recharge, which automatically tops up your data when it runs low (it's off by default, so only those who want it can turn it on). If you'd like to reduce the worry of "running out and not being able to check the map," these features are worth considering too. You can check your remaining data anytime from My Account.
Note that Bloomy plans are data-only (no phone number, SMS, or voice calls). If you need local voice calls or a phone number, you can use app-based calling over data such as WhatsApp, or look into a separate option that includes a number.
Choose and compare capacity with Bloomy
Once you have a sense of the capacity that fits you, all that's left is to pick a plan. On Bloomy's comparison page, you can specify your destination country or region, data amount, and number of days to line up and compare plans that match. Use the estimates in this article — "short trip, smaller amount," "a week, typical use," "long stay, unlimited" — as your starting point.
Before you set things up and get started, it's also reassuring to check that your smartphone supports eSIM. It's worth confirming your compatible devices ahead of time. Plan details and pricing are subject to change, so please check the latest information at the time of purchase.
