Which has the bigger carry-on allowance, Southwest or Sun Country?

Southwest: 24 × 16 × 10 in (61 × 41 × 25 cm). Sun Country: 24 × 16 × 11 in (61 × 41 × 28 cm), up to 35 lb (15.9 kg). Sun Country allows the larger bag.

Are Southwest and Sun Country partners?

They aren't in the same alliance (Southwest: none; Sun Country: none), so miles and status generally don't transfer between them.

WN vs SY · 2026 comparison

Southwest vs Sun Country

Q: Do Southwest and Sun Country include a carry-on on basic economy?

Southwest: Even the Basic fare includes a carry-on and a personal item. Checked bags cost extra on Basic, Choice and Choice Preferred fares. Sun Country: Fares include only a personal item. Buying a carry-on early is cheapest.

Southwest wins on a carry-on on its cheapest fare and a more generous carry-on weight limit; Sun Country wins on a bigger carry-on, a bigger personal item and cheaper checked bags. Here's how they compare on bags, fees, comfort, reliability and loyalty.

Verified Oct 17, 2026By Steven MoHow we check Report a correction

Southwest

Wins 2 categories

A carry-on on its cheapest fare
A more generous carry-on weight limit

Sun Country

Wins 3 categories

A bigger carry-on
A bigger personal item
Cheaper checked bags

Quick verdict

Southwest wins on a carry-on on its cheapest fare and a more generous carry-on weight limit; Sun Country wins on a bigger carry-on, a bigger personal item and cheaper checked bags. Check the cheapest fare's bag rules before you compare prices.

Carry-on size: Southwest: 24 × 16 × 10 in · Sun Country: 24 × 16 × 11 in
Carry-on on the cheapest fare: Southwest: Included on every fare · Sun Country: Costs extra on basic fares
First checked bag (regular economy): Southwest: $45 · Sun Country: $34–$45

Side by side

	Southwest	Sun Country
Bags
Carry-on size	24 × 16 × 10 in	24 × 16 × 11 in
Carry-on on the cheapest fare	Included on every fare	Costs extra on basic fares
Carry-on weight limit	None published	35 lb (15.9 kg)
Personal item	16.25 × 13.5 × 8 in	17 × 13 × 9 in
First checked bag (regular economy)	$45	$34–$45
Network
Alliance	None	None
Loyalty program	Rapid Rewards	Sun Country Rewards
Main hubs	DEN, LAS, MDW, BWI, DAL	MSP

Highlighted values are better for travelers. Fees are for U.S. domestic economy flights; on-time data is 2025 U.S. DOT figures for each airline's own flights.

Bags and fees

Southwest allows a carry-on up to 24 × 16 × 10 in (61 × 41 × 25 cm), and Sun Country up to 24 × 16 × 11 in (61 × 41 × 28 cm), so Sun Country's is roomier.

Southwest includes it on every fare, while Sun Country charges for it on its cheapest fare.

Sun Country caps carry-ons at 35 lb (15.9 kg); Southwest publishes no limit.

Personal items: 16.25 × 13.5 × 8 in (41 × 34 × 20 cm) on Southwest, and 17 × 13 × 9 in (43 × 33 × 23 cm) on Sun Country.

A first checked bag on Southwest costs $45 on flights within the U.S. mainland, and a first checked bag on Sun Country costs $34–$45 on all Sun Country flights.

Basic economy

Southwest (Basic): Even the Basic fare includes a carry-on and a personal item. Checked bags cost extra on Basic, Choice and Choice Preferred fares.

Sun Country (Best fare): Fares include only a personal item. Buying a carry-on early is cheapest.

Loyalty and where they fly

Southwest is not in an alliance and Sun Country is not in an alliance.

Loyalty programs: Rapid Rewards (Southwest) and Sun Country Rewards (Sun Country).

Southwest's main hubs are Denver (DEN), Las Vegas (LAS), Chicago (MDW), Baltimore (BWI), Dallas (DAL). Sun Country's are Minneapolis (MSP). The best choice often comes down to which airline flies nonstop from your airport.

Which should you book?

Choose Southwest if you want…

a carry-on on its cheapest fare
a more generous carry-on weight limit
nonstops from DEN, LAS, MDW

Choose Sun Country if you want…

a bigger carry-on
a bigger personal item
cheaper checked bags
nonstops from MSP

On a route both fly, the cheaper ticket isn't always the cheaper trip: add the bags you'll actually bring, and check the fare rules before you book.