Read the figure your phone already recorded at home — it is a far better predictor than any table, because it is your own habits rather than an average
Every phone keeps a running count of mobile data used. Look at a full month, divide by thirty, and you have a daily figure that reflects the way you actually use a phone.
On an iPhone
- Settings › Mobile Data (or Cellular)
- Scroll to Current Period
- Note the date it was last reset — divide the total by the days since
- Below it, each app is listed with its own total
On Android
- Settings › Network & internet › Mobile network
- Tap App data usage
- Choose a full month in the date selector
- Each app is listed with its own total
Adjusting the Figure for a Trip
- Subtract what you will not do abroad — work video calls on a home connection, for instance
- Add navigation, translation and ride-hailing, which most people barely use at home
- Subtract a share for hotel, café and airport Wi-Fi, which usually covers the evenings
- Add a margin if you plan to tether a laptop or a second traveller
Check the per-app list before you decide. If one video or photo-backup app dominates the total, changing its settings for the trip will cut your requirement more than buying a larger plan would.
Then round up. A slightly larger plan costs a little; running out on the far side of a city with no Wi-Fi costs an afternoon. If you would rather start small, topping up mid-trip is possible — see Can I Top Up My Plan?
