How Much eSIM Data Do I Need? A Simple Way to Work It Out

Short answer: most travellers need 1 GB per week for maps and messaging, 3–5 GB per week for normal use, and 10 GB or more per week only if they stream video or work remotely. Almost everyone over-buys, because the number that feels safe is three times the number that is actually used.

What each activity really costs

These are typical figures. Your mileage varies with quality settings, but the orders of magnitude hold.

• Turn-by-turn navigation — about 5 MB per hour. Ten hours of driving is 50 MB.
• WhatsApp or iMessage text — negligible. Thousands of messages fit in tens of megabytes.
• WhatsApp voice call — roughly 5 MB per minute at the high end; usually less.
• Email and web browsing — about 10–20 MB per hour.
• Social media scrolling — 50–150 MB per hour, because it is mostly video now.
• Music streaming — about 40–80 MB per hour at standard quality.
• Video streaming — 700 MB per hour at 720p, and 2–3 GB per hour at 1080p or higher.
• Video calls — 500 MB to 1.5 GB per hour.
• Photo backup to the cloud — 2–4 MB per photo, and this is the silent plan-killer.

The two-minute method

1. Count your travel days.
2. Pick your profile: 0.15 GB/day for light use, 0.5 GB/day for normal, 1.5 GB/day for heavy.
3. Multiply. A ten-day normal trip is about 5 GB.
4. Subtract Wi-Fi. If your hotel has decent Wi-Fi and you are out sightseeing all day, take 20–30% off.
5. Do not round up twice. Buy the size you calculated, and top up if you are wrong.

Topping up mid-trip is easy and usually cheaper per gigabyte than the next size up. Buying a 20 GB plan for a five-day trip is money handed over for nothing.

The four settings that decide everything

Change these before you fly and a 3 GB plan lasts a week:

1. Turn off photo/cloud backup over mobile data. Let it run on hotel Wi-Fi overnight.
2. Turn off automatic app updates over mobile data. An OS update can be several gigabytes.
3. Set video apps to standard or low quality. The difference between 720p and 1080p on a phone screen is small; the difference in data is a factor of three.
4. Download offline maps, playlists and shows on Wi-Fi before you leave.

One traveller's 20 GB and another traveller's 3 GB are usually the same trip with different backup settings.

Plan sizes by trip type

• Weekend city break — 1–3 GB.
• One-week holiday, normal use — 3–5 GB.
• Two-week holiday — 8–10 GB.
• Two weeks of remote work — 20 GB or an unlimited plan.
• A month abroad — 20 GB or unlimited, depending on whether you have reliable Wi-Fi where you sleep.
• Southeast Asia or Latin America with heavy ride-hailing and delivery apps — add about 30%; those apps are used constantly, though each use is small.

How to check your own numbers

Before the trip, look at your phone's data usage for a normal week at home, then subtract what you did on home Wi-Fi. On iPhone: Settings, Cellular, and scroll to the per-app list. On Android: Settings, Network and internet, and open the data usage screen. That number, adjusted for how much more you will use maps and how much less you will stream, is a better estimate than any generic table.

Frequently asked questions

How much data does Google Maps use per day?

About 5 MB per hour of active navigation, so even a heavy sightseeing day is well under 100 MB. Downloading an offline region in advance cuts it close to zero.

Is 1 GB enough for a week abroad?

For maps, messaging and occasional browsing, yes. It is not enough if you scroll social media daily or upload photos as you take them.

How much data does WhatsApp use?

Text is negligible. Voice calls are a few megabytes per minute, video calls far more. Sending photos and videos is what adds up — a 30-second video clip can be 30 MB.

Should I buy unlimited instead of guessing?

If you work remotely, stream, or hate thinking about it, unlimited is worth the premium. For a normal holiday it usually is not — and most unlimited plans slow down after a daily high-speed allowance anyway.

What happens if I run out of data mid-trip?

The line stops passing data. You are not billed extra. You buy a top-up, it applies to the same eSIM, and you carry on — usually within a couple of minutes.

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