Two very different halves of one trip. The city half uses roughly twice what the coast half does, and one plan has to cover both.
The standard Portuguese week is a few days in Lisbon and then south to the coast, or the same thing in reverse. It is a good trip and an awkward one to size a data plan for, because the two halves place quite different demands on your phone and people tend to size for whichever half they are thinking about when they buy.
Lisbon uses more than you expect
Lisbon is a navigation city. The streets run at angles, the hills mean the shortest route is rarely the sensible one, and almost everyone spends the first two days with a map open more or less continuously. Add looking up which viewpoint is worth the climb, checking whether a restaurant needs booking, and photographing a great deal, and a Lisbon day sits at the heavier end of a European city break.
The trams and the funiculars have another effect people do not anticipate: a good deal of waiting, which is a good deal of scrolling.
The Algarve uses considerably less
The coastal half is a different pattern entirely. You are usually based in one place, walking to the same beach and the same few restaurants, and the phone comes out in the evening rather than all day.
What raises it is accommodation. Algarve rentals and smaller hotels vary enormously in Wi-Fi quality, and a week somewhere with a weak shared connection means everything that would normally happen on Wi-Fi happens on your plan instead — photo backup especially, after a week of beach photographs.
THE HALF PEOPLE SIZE FOR
Most people buy their plan while thinking about the beach, because that is the half they booked the trip for.
Size for the city half. It is the one that consumes, and a plan that covers Lisbon comfortably will cover the Algarve with room to spare.
Getting between the two
The train south is well covered along the route, and the drive is straightforward on the motorway. Neither leg is a connectivity problem. If you are stopping somewhere inland on the way — the Alentejo is worth the detour — expect the same thinning that rural areas produce anywhere, and download the map before you leave the city.
How much for the week
Concrete reference points, for a seven-night trip. These assume photo backup set to Wi-Fi only and no video streaming on mobile data — change either and the figures rise sharply.
Three nights Lisbon, four nights Algarve, standard sightseeing: roughly 3 to 5GB.
Five nights Lisbon, two nights coast, heavy navigation and lots of photographs: roughly 5 to 8GB.
Two nights Lisbon, five nights on a beach with good apartment Wi-Fi: roughly 1.5 to 3GB.
Any of the above with weak or shared accommodation Wi-Fi: add 2 to 4GB, because everything that would have run on Wi-Fi runs on the plan instead.
These are reference ranges rather than measurements. Individual habits move them more than the itinerary does — someone who video-calls home nightly will exceed all of these, and someone who barely opens their phone will use a fraction. Treat them as a starting point and adjust for whichever of those two you are.
Our Portugal plans start at $9.99 and the plan page shows current sizes. For the standard split, the middle of the ladder over a comfortable window covers it with room to spare.
A note on longer stays
Portugal is one of the more common places to spend a winter rather than a week, and the arithmetic for months is different from the arithmetic for days.
Setting up
At home, before you fly, on your own Wi-Fi. Your usual number stays on the phone for calls and texts throughout.
