CALGARY - WestJet plans to reduce how much its passengers carry on, a move the airline says will make its increasingly full Boeing 737s less crowded and help align its baggage rules with those of other airlines.

After April 4, travellers will only be allowed one piece of carry-on luggage and one personal item. The Calgary-based airline had previously allowed passengers to bring two carry-on items and a personal item.

Carry-on luggage includes items such as suitcases, backpacks or bags and must fit a specific sizing device before boarding.

The maximum size for the carry-on luggage is 21 inches by nine inches by 15 inches (53.3 by 22.8 by 38.1 centimetres) — about the same as the larger of two carry-ons allowed under the previous standards.

Personal items include smaller things such as small purses, laptop bags or child restraint devices. For parents travelling with infants, a diaper bag is also permitted over and above the carry-on allowance.

Items that don't fit the size requirements will have to be checked at the baggage counter before departure and picked up at a carousel after landing.

The changes were announced Tuesday as WestJet reported its February load factor — a measure of how full its planes were — rose to 86.1 per cent, up from 82.7 per cent in February 2012.

WestJet spokesman Robert Palmer says the airline has hit record load factors since last summer and there's no sign of a let up ahead.

"We're flying our aircraft fuller than we've ever flown them in our 17-year history, so there isn't always enough room," Palmer said.

"This will ensure that everybody has an equal and ample opportunity to get their items in the overhead bins."

In addition, WestJet wants to standardize the luggage rules to accommodate travellers who will transfer to the smaller Bombardier Q400 regional turboprop planes that will be flown by WestJet Encore.

"We're going to have one allowance for the two sizes of aircraft," Palmer said.

Similarly, WestJet said the new rules will also ease connections with about 30 other airlines.

"This baggage allowance of one carry-on bag plus one personal item is pretty much the world standard," Palmer said.

"To minimize confusion and make it more convenient for our guests, it just makes sense to use the same baggage allowance."

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