Last updated: July 24, 2026
Whether you're heading off for a short trip, a few weeks of travel, or a longer stay abroad, one question comes up again and again: how many GB of eSIM data do I actually need? The short answer is that you can estimate it well enough with a simple formula — number of days × how heavily you use your phone each day. This guide breaks down typical data needs by trip length and by activity, explains how Wi-Fi at your accommodation changes the math, and shows what to do if you think you might run short.
- Data estimates by length of stay
- How much data common activities use per day
- How to adjust when you have Wi-Fi
- What to do if you're running low
- How to pick the right size plan for you
Your data needs come down to days × usage style
Two things drive how much data you'll need: how long you're staying and how much you use your phone each day. Someone who mainly uses maps, messaging apps, and quick searches will burn through far less than someone streaming video and making video calls — even on an identical two-week trip.
The easiest approach is to settle on a rough daily figure first, then multiply it by your number of days. Adding a little headroom on top is worth it: busy sightseeing days, unexpected detours, and long waits at airports all push usage higher than you'd expect.
Data estimates by length of stay
The table below assumes you're relying mostly on mobile data while you're out and about, without much Wi-Fi. Real-world usage varies a lot, so treat these as a starting point for planning rather than exact figures.
| Length of stay | Light (messaging & maps) | Moderate (browsing & social) | Heavy (video & calls) |
|---|---|---|---|
| 3 days | ~1–2GB | ~3GB | 5GB+ |
| 1 week | ~3GB | ~5–7GB | 10GB+ |
| 2 weeks | ~5GB | ~10GB | 20GB+ |
| 1 month | ~10GB | ~20GB | Consider an unlimited-style plan |
For longer stays with heavy daily use, a large-data or unlimited-style plan can make more sense than topping up repeatedly. Keep in mind that unlimited-style plans generally come with a fair usage policy, and speeds may be adjusted after a certain amount of use. Check the current terms on the plan page before you buy.
How much data common activities use
Not sure whether you're a light, moderate, or heavy user? It's easier to judge by thinking about the apps you actually open. The figures below are general estimates and will shift depending on your video quality settings and network conditions.
| Activity | Rough usage per hour | Notes |
|---|---|---|
| WhatsApp & text messaging | Very little | Often just tens of MB across a whole day |
| Maps & navigation | Tens of MB | Adds up on days with a lot of moving around |
| Social media (image-heavy) | Several hundred MB | Autoplay video pushes this up quickly |
| Music streaming | Around 100MB | Downloading playlists in advance saves a lot |
| Video streaming (standard quality) | ~0.5–1GB | HD and 4K use considerably more |
| Video calls | ~0.5–1GB | Long calls add up fast |
A single evening of streaming or one long video call can easily pass 1GB on its own. On the other hand, if your days are mostly messaging and navigation, you may need far less data than you'd assume.
Adjusting your estimate when you have Wi-Fi
Many travellers have reliable Wi-Fi at their hotel, apartment, or wherever they're staying. If that's you, save the big stuff — streaming, app updates, photo backups, cloud syncs — for when you're connected to Wi-Fi. Your eSIM data then covers mainly messaging, maps, and quick lookups while you're out, which means you can comfortably choose a smaller plan.
Wi-Fi is convenient, but it isn't always dependable — hotel connections can be slow, and some days you'll barely be at your accommodation at all. Choosing a plan with a bit of extra room for time spent out of the house makes the trip a lot less stressful.
What to do if you're running low
If your data starts looking tight partway through the trip, you have a couple of options. One is to build in headroom from the start by choosing a slightly larger plan than your estimate. The other is to buy additional data when you need it. Which works better depends on how you travel.
- Hard to predict, out and about a lot: go bigger from the start, or look at an unlimited-style plan for longer stays
- Usually a light user, just want a safety net: start with a standard size and top up if needed
If you'd like to keep your existing phone number active while covering your data with an eSIM, we've laid out how that combination works — including what happens to your number — in Keeping your phone number while travelling: how a data eSIM fits alongside your existing plan. It's a useful companion read.
What a data-only eSIM can and can't do
Bloomy plans are data-only. This matters just as much as picking the right size, so we want to be upfront about it: a data-only eSIM does not come with a phone number, and it can't make or receive voice calls or SMS text messages.
What you can do is use app-based calling as normal — WhatsApp, Messenger, FaceTime, and similar apps all work over data. The limitation applies only to traditional calls and texts tied to a phone number. If you expect to need SMS verification codes from your bank, or to receive calls on your regular number while you're away, plan ahead: keep your existing SIM active for those, or look at a plan that includes a number.
One more thing to keep in mind: actual speeds and coverage depend on the local partner networks, your device, and where exactly you are, so performance will vary from place to place. Unlimited-style plans are also subject to a fair usage policy.
Who should size up, and who can size down
To wrap up, here's a quick way to sanity-check your choice so you don't end up paying for data you'll never touch — or running dry halfway through.
Go with a larger plan if you...
- Spend most of the day out, streaming or making video calls on the move
- Have no Wi-Fi where you're staying, or it's unreliable
- Genuinely can't predict your usage and would rather not think about it
A smaller or standard plan is likely enough if you...
- Mostly stick to messaging, maps, and light browsing
- Have solid Wi-Fi at your hotel or accommodation
- Are travelling short-term and don't do much heavy streaming
Find the right Bloomy plan for your trip
Once you have a sense of your trip length and usage style, the rest is straightforward. Head to the Bloomy eSIM comparison page to browse plans by data allowance and validity period. If you'd like to see how installation works before you commit, take a look at the setup guide, and the FAQ covers the finer details.
Plan contents, data allowances, pricing, and terms are subject to change (information current as of July 2026). All prices are shown in USD — please confirm the latest details and the final price on the comparison page at the time of purchase.
