A Canada trip is rarely one shape. It might be two eastern cities with a train between them, a fortnight of mountain driving out of Banff, or Vancouver plus a ferry and an island. They ask very different amounts of a phone, and not in the way most people expect: the remote days are not the expensive ones.
The figure, before the reasoning
For one week, most travellers land between 3 GB and 5 GB. Light use — maps in short bursts, messaging, a hotel connection every evening — sits near 3 GB. Ordinary use, where the phone also carries tickets, photographs and a call home, sits nearer 5 GB. A heavy week, meaning a laptop sharing the connection or uploads every day, wants about 10 GB.
A fortnight is not simply double: light use still fits inside 5 GB, and ordinary use lands near 10 GB. Two heavy weeks are the one case the sizes do not answer neatly, and that has a section below.
The handoffs are the expensive part
Canadian itineraries are built out of transfers that look interchangeable on a map and are not. At Toronto Pearson the UP Express platform is beside Terminal 1, so an arrival at Terminal 3 begins with the Terminal Link before the train to Union Station. At Montréal-Trudeau the 747 runs a short route to Lionel-Groulx and a longer one downtown, and Dorval intercity rail needs a different shuttle from departures, Door 8. At YVR the Canada Line station sits between the international and domestic terminals, while Tsawwassen means changing at Bridgeport onto a separate bus, with ticket, check-in and boarding handled apart.
None of those is a large download. Each is a small pile of lookups — which platform, which of two routes, which door, where the booking went — and they cluster at the worst moment.
Count your handoffs, not your nights
Nights are the wrong unit here. Mark every point on the itinerary where you change vehicle, terminal, town or booking: airport to train, train to an address, town to a park gate, bus to ferry. A week in Toronto and Montréal with rail in the middle has perhaps six; a Rockies loop with a shuttle most mornings, closer to fifteen.
Then do three crude sums. Allow roughly 0.2 GB per handoff. Allow another 0.2 GB for each day out and reachable: messages, weather, the background drip of a phone in a pocket. Allow about 0.5 GB for every half hour of video call. A nine-day eastern trip with six handoffs, nine days out and three calls home lands near 4.5 GB — take the next size up, not the one that just fits. The arithmetic is rough on purpose: it puts the number where your trip is, not where an average one is.
Three itineraries that behave nothing alike
The eastern pair. Toronto and Montréal with rail between them is the lightest of the three. Lookups are short and frequent, hotel connections take the evenings, and the train itself is a few quiet hours.
The Rockies. Driving days out of Banff toward Lake Louise and the Icefields Parkway invert the usual assumption. Parks Canada advises that the Parkway has no cell coverage and limited services, so the hours of biggest scenery are hours of almost no consumption. What a mountain day spends, it spends that morning in town.
Vancouver and the water. The city behaves much like Toronto. The ferry does not: service can end once a boat leaves terrestrial range, so the crossing is a gap, not an hour of scrolling. Size for the terminal.
One line runs through all three. Canada sits five to nine hours behind most of Europe, and the overlap where both ends are awake is short, so contact compresses into two or three long calls rather than a dozen brief ones. Long calls are what a careful estimate misses.
Reading your number against what Canada lists
The Canada page carries 1 GB over seven days, 3 GB over fifteen days, then 3 GB, 5 GB and 10 GB over thirty days, with two much larger sizes above those. The gap matters more than the rungs: nothing sits between 10 GB and the large sizes, so two heavy weeks pick between overbuying and topping up on the way. Where the selected plan supports a top-up, a week that ran hotter than planned is handled on the profile already installed.
The current list sits on the Canada plans page, and for most itineraries the sensible default is the 30-day option that carries 10 GB: it covers an ordinary fortnight, absorbs a bad week, and leaves room around the flight home. A three-night city break is better served by something smaller. Whether validity begins at installation or at first connection is stated on the offer you choose, so check that before you install; the steps are in the installation guide.
What to change when the estimate looks high
Four habits move a Canada figure more than anything else does.
Turn off automatic photo and video upload. A week in the mountains produces far more of both than a week in a city, and the uploads run while you drive, unnoticed.
Read the day in town. Route, closures, forecast and any reservation are cheap on a hotel connection and awkward everywhere else; taken together they use one sitting, not five.
Load the long hours the night before. The eastern train and the drive north from Banff are both stretches in which nothing needs to arrive live.
Where the selected plan and your device allow, sharing to a laptop is the single habit that can double an estimate. If anyone is working on this trip, size for the laptop and treat the phone as a rounding error.
Tip: A Lake Louise morning is three confirmations rather than one. Parks Canada shuttle rules can require a reservation, a Park and Ride check-in and a separate park entry, and the procedure changes between seasons. Settle all three the evening before, in Banff, and the mountain day itself asks almost nothing of the plan.
A crossing into the United States is a separate plan
Plenty of Canadian itineraries touch the border: Niagara from the Ontario side, the run down from Vancouver to Seattle, the crossing between Detroit and Windsor. A Canada plan is sold for Canada. The label does not extend to the United States: the territory list on the offer you choose decides, not a route map or a destination name. A day on the other side is a second purchase.
Five short answers
What does a week in Canada need? Light use about 3 GB, ordinary use 5 GB, and 10 GB where a laptop shares the connection.
And a fortnight? About 5 GB light and 10 GB ordinary; two heavy weeks need a larger size, or a top-up where the plan supports one.
Do the Rockies need more? Less, not more. Parks Canada advises there is no cell coverage on the Icefields Parkway, and the spending happens in Banff that morning.
Does a Canada plan cover a day in the United States? No. They are separate purchases, and the territory list on your offer settles it.
What if the allowance runs out? Where the selected plan supports a top-up, that is the simplest answer; otherwise a second purchase covers what is left.
