In short: It depends on what you do. Messages and maps need very little, streaming and video calls need a lot more. With an unlimited plan the question stops mattering.

Where your data actually goes

Most people underestimate how unevenly data use is distributed. Chatting and email barely register. Video is the one item that outweighs everything else. As a rough guide, per hour:

  • Messaging, email, reading the news: a few megabytes. Even heavy chatting usually stays under 1 GB a month.
  • Navigation: around 5 to 10 MB an hour, so a long drive costs almost nothing.
  • Music streaming: roughly 70 to 150 MB an hour.
  • Social media with video in the feed: about 500 MB to 1 GB an hour.
  • Video calls: around 500 MB to 1.5 GB an hour.
  • Video streaming: about 700 MB an hour in SD, 1 to 3 GB in HD, considerably more in 4K.

What that means over a month

  • Light use: messaging, email, the occasional map. Often 3 to 5 GB a month is enough.
  • Normal use: daily social media, music on the move, the odd video. Usually 10 to 20 GB.
  • Heavy use: series on the train, long video calls, hotspot for the laptop. 50 GB and up comes quickly.
  • Traveling: budget for more as a rule. Without familiar Wi-Fi everything runs over mobile, and maps, translation and booking apps run all day.

Why the calculation usually misses

Two things make the estimate unreliable. First, use swings sharply from month to month: a vacation, a move, or a week without Wi-Fi at home doubles it easily. Second, your own behavior changes as soon as the allowance runs low. If you start saving video for Wi-Fi on the 20th of the month, you have not found the right data package, you have adapted to one that is too small.

Which is why the honest answer is often this: you do not need a number, you need no ceiling.

The alternative: do not count at all

With Simsalasim your data is unlimited in 100 countries, for 10 € a month. There is no allowance to use up, nothing to top up and no throttling at a hidden threshold. So you never have to watch your usage, at home or on vacation.

Alongside that comes unlimited Talk+Text to 50 countries and all Simsalasim users. Calls and texts follow the destination you are calling, not where you happen to be.