How Much eSIM Data Do You Actually Need?

At home your phone sits on wifi for most of the day, so your mobile data figure on your monthly bill reflects only the hours you were out. That number is a poor predictor of a trip, in both directions.

It understates travel usage because abroad your phone is on cellular data all day, including the hours you would normally have been on your home or office wifi. It overstates travel usage because the activities that consume the most data at home — long video sessions, large downloads, streaming music while you work — mostly do not happen while you are walking around a city you came to look at.

The result is that most travellers use less total data than they fear, but spread across more hours than they expect. Sizing on activity rather than on your monthly bill is the accurate approach.

If you use your phone strictly as a tool — navigating with a maps app, sending text messages, pulling up a boarding pass or train ticket, translating a menu — you need very little. This style of use runs to roughly 200 to 300 MB per day.

At that rate a 3 GB plan comfortably covers a week and a 5 GB plan covers two. Text-based apps are extremely efficient, and satellite navigation itself uses no data at all: GPS positioning is a one-way radio signal from satellites, and the only thing your plan pays for is downloading the map imagery as you move.

Most travellers land here. Alongside maps and messaging you post a few photos, scroll a feed while queueing, and make voice calls home over WhatsApp. This runs to roughly 500 to 800 MB per day.

For a one-week trip at this rate, 5 GB gives you a comfortable margin and 10 GB gives you a generous one. For two weeks, 10 GB is the natural size.

The variable that moves this number most is video inside social feeds. Scrolling a text-and-photo feed is cheap; scrolling a feed that autoplays video is several times more expensive for the same ten minutes. Turning off autoplay in your social apps is the single highest-leverage change you can make before a trip.

Video is what genuinely consumes data. Streaming video, long video calls, or tethering a laptop to work from a cafe can push you past 1 to 2 GB per day without much effort.

If you plan to work from the road, share your connection with a partner or children, or watch anything on a long train journey, look at 15 GB or 20 GB, or a reloadable plan you can extend as you go.

One number worth internalising: an hour of standard-definition streaming video uses somewhere around 0.7 GB, and an hour of high-definition streaming uses several times that. A single evening of HD video can exceed an entire week of maps and messaging.

Approximate figures, useful for building your own estimate rather than trusting a category label. All of these vary with app settings, image quality and network conditions.

Maps and navigation: roughly 5 to 10 MB for a half-hour of active turn-by-turn navigation. Text messaging over WhatsApp, iMessage or Signal: a few megabytes a day even for heavy chatters. Voice calls over the internet: roughly 0.5 MB per minute. Video calls: roughly 5 MB per minute, which is ten times the voice figure and the reason a long family video call is a meaningful chunk of a small plan.

Scrolling a social feed: roughly 100 to 150 MB for ten minutes if video autoplays, far less if it does not. Uploading a photo: a few megabytes each at normal quality. Uploading a short video: tens of megabytes. Streaming music: roughly 50 to 100 MB an hour at standard quality. Streaming video: roughly 0.7 GB an hour at standard definition, and considerably more above that.

If you would rather not do the arithmetic, the calculator at /data-calculator turns your trip length and habits into a plan size.

The activities that surprise people are the ones they never chose to do. Automatic photo backup to a cloud service is the biggest single offender: a day of holiday photography can be several gigabytes, and if backup is set to run on any connection it will quietly upload all of it over your travel plan.

App updates are the second. A phone that decides to update fifteen apps on cellular data can consume more in ten minutes than you used all week. Podcast and music apps that pre-download new episodes are the third.

All three are solved by the same two settings, and it is worth doing them before you leave: set photo backup to wifi-only, and set app updates and automatic downloads to wifi-only. This is the difference between a 5 GB plan being generous and being gone by Wednesday.

Almost everyone assumes navigation is the expensive part of travel data, and it is close to the cheapest. GPS positioning does not use your data plan at all. What uses data is downloading map tiles for areas you have not viewed before, and that is a small, front-loaded cost.

You can reduce it to essentially zero by downloading offline maps for your destination over wifi before you travel. Both major maps apps support this. An offline map of a city area is typically a modest download and then costs you nothing for the rest of the trip.

The practical implication: do not buy a bigger plan because you expect to navigate a lot. Navigate all you like.

The reverse error is equally common. A modern phone camera produces large files, a good day of sightseeing produces a lot of them, and cloud backup services are designed to upload continuously so that nothing is ever lost.

A single day of enthusiastic photography can generate several gigabytes of uploads. Over a two-week trip that comfortably exceeds any plan you were likely to buy, and it happens in the background while you are doing something else.

The fix is not to stop taking photos. It is to set backup to wifi-only and let it catch up at the hotel each night, which is both cheaper and better for your battery.

The most reliable estimate is your own historical data, and both phone platforms will tell you.

On iPhone, open Settings, then Cellular (called Mobile Data in some regions), and scroll to the usage figures with a per-app breakdown underneath. The catch is that the total is cumulative since you last reset it, which for many people is since they bought the phone. Reset the statistics at the start of a normal week, check it seven days later, and you have a real number.

On Android, open Settings, then Network and internet, then the data usage screen for your SIM. Android gives you a monthly cycle and a per-app breakdown by default, which is more immediately useful. Once you are travelling, both platforms show usage per line, so you can watch the travel eSIM specifically rather than the total.

Running out is a recoverable problem, and it is a much cheaper mistake than overbuying. You can top up an active vigxo eSIM from your dashboard and the new data applies to the profile already installed on your phone — nothing to reinstall, no new QR code, no gap in service.

This is why the honest advice is to buy for your realistic everyday use rather than your worst imaginable week. A 5 GB plan topped up once costs less than a 20 GB plan bought defensively and half used.

If you are somewhere with no connection at all when you run out, hotel or cafe wifi is enough to complete the top-up, since the purchase itself needs only a brief connection.

Plans marketed as unlimited generally include a fair-use threshold, after which speeds are reduced — sometimes to a point where video and large downloads become impractical while messaging still works. That is not necessarily a bad deal, but it means the word describes the billing, not the experience.

The second thing to check on any unlimited plan is whether hotspot use is included or excluded, because it is frequently excluded or capped separately. If your reason for wanting unlimited data is tethering a laptop, that exclusion removes the entire point.

A fixed plan with a clear number is easier to reason about, and if you have sized it from actual activities rather than anxiety, it is usually cheaper as well.

Estimate your daily figure from the activity list rather than the category label, multiply by trip length, then add about twenty per cent of headroom. Do not add a hundred per cent — that is how people end up paying for data they will never use.

For most travellers the answer lands on 5 GB for a week and 10 GB for two, with heavier users and anyone tethering a laptop moving one size up. If you want the arithmetic done for you, /data-calculator does it, and the plan pages show the exact price for each size in your own currency.