I. Why Budget Airlines Restrict Carry-On Luggage
Budget airlines operate on an ultra-low-cost model that strips away everything except the core flight service. Carry-on baggage policy is one of the most significant cost levers—and the area where passengers most frequently get caught.
Traditional full-service carriers (like Air China, China Eastern, China Southern) typically include free checked bags and two pieces of carry-on. Budget carriers restrict carry-on to 7-10 kg per passenger, with excess weight requiring additional purchase.
Why weight matters financially: Fuel consumption scales directly with aircraft weight. Each additional kilogram adds roughly 0.03-0.05 liters of fuel per flight segment. On an A320 carrying 180 passengers, if each passenger carries 5 kg extra, the aircraft burns an additional 27-45 kg of fuel—costing approximately $17-28 per flight in additional fuel. Annualized across thousands of flights, this represents millions in operational costs.
Cabin luggage weight also affects aircraft balance and trim. Carry-on bags concentrate in overhead bins near the forward cabin; exceeding design limits can impact center of gravity. Budget airlines enforce strict weight limits to ensure precise load planning and reduce operational costs.
II. 2026 Major Budget Airline Carry-On Policy Comparison
2.1 Chinese Budget Airlines
Spring Airlines (春秋航空) China’s largest budget carrier operates primarily Japan, Korea, Thailand international routes plus some domestic services with the strictest carry-on policy among domestic LCCs:
| Cabin Class | Carry-On Allowance | Size Limit | Weight Limit | Overage Handling |
|---|---|---|---|---|
| Promo fares | No free carry-on | - | - | Must purchase |
| Saver fares | 1 piece | 20×30×40cm | 7kg | ¥140/piece |
| Standard fares | 1 piece | 20×30×40cm | 7kg | ¥140/piece |
| Flex fares | 1 piece | 20×30×40cm | 7kg | ¥140/piece |
Spring’s 20×30×40cm requirement is significantly smaller than the 20×40×55cm standard used by most carriers. A standard laptop backpack (typically 20×35×45cm) exceeds this limit. Most adult backpacks are too large—passengers frequently get caught at the gate.
9 Air (九元航空) 9 Air, a subsidiary of Juneyao Air based in Guangzhou and Guiyang, operates domestic and Southeast Asia routes:
- Free carry-on: 1 piece, 20×30×40cm, 7kg
- Excess: Purchase checked baggage (10kg+, approximately ¥80-150)
- Note: Some “bare fare” options exclude ALL baggage
West Air (西部航空) Based in Chongqing and Zhengzhou, West Air operates domestic budget routes with policies similar to 9 Air: 1 piece, 20×30×40cm, 7kg. Checked bags must be purchased separately at approximately ¥100 for 10kg.
2.2 International Budget Airlines
AirAsia Southeast Asia’s largest budget carrier with extensive routes from Chinese cities:
| Cabin Class | Carry-On Allowance | Size Limit | Weight Limit |
|---|---|---|---|
| Regular fares | 1 piece | 56×36×23cm (~within 7kg) | 7kg |
| Premium Flatbed | 2 pieces | Same | 7kg×2 |
AirAsia’s 56×36×23cm is far more generous than Spring’s box—roughly equivalent to a standard carry-on suitcase. However, the 7kg weight limit is still strictly enforced, with gate weighing common on many routes.
Ryanair (Europe’s largest LCC) Known for the most严格执行 carry-on policy:
- Small carry-on (free): 40×20×25cm—must fit under front seat
- Large carry-on (paid): 55×40×20cm—for overhead bin (~$8-20, or with Priority Boarding)
- 2024-2026 policy: Only “Priority” passengers may bring large carry-on bags to cabin
Ryanair’s policy is complex and frequently changes. Current rules: regular fare passengers may only bring one small bag (40×20×25cm) to the cabin; larger bags must be checked (at 2-3× normal checked bag rates). Many passengers get caught at the gate and forced to pay premium oversize/overweight fees.
EasyJet (UK’s largest LCC) Relatively passenger-friendly carry-on policy:
- Free carry-on: 1 piece, 45×40×20cm, no official weight limit (practically ~10kg enforced)
- Additional piece: Purchasable on easyJet website, £6-15/piece
EasyJet does not weigh carry-on bags at the gate as standard practice. However, cabin crew retain authority to require visibly overweight bags be checked.
Cebu Pacific (Philippines LCC) Popular for Southeast Asia routes:
- Base fare: No carry-on included, must purchase separately
- With-baggage fare: 1 piece carry-on, varying size/weight by route (~7-10kg)
Promotional Cebu Pacific fares typically exclude ALL baggage—always verify when booking.
Jetstar (Australia/Southeast Asia LCC)
- Starter base fare: No carry-on
- Starter Plus: 1 piece, 7kg carry-on included
- Jetsmart (Thailand domestic): 1 piece, 7kg included
III. Common Carry-On Violations & Practical Solutions
3.1 Size Overages: Real Gate Cases
The most common violation is backpack dimensions exceeding 20×30×40cm (Spring Airlines). Testing with common bags:
Case Study (March 2026, Shanghai Hongqiao–Osaka):
- Backpack actual size: 20×35×45cm
- Spring requirement: 20×30×40cm
- Result: Passenger required to check bag
- On-spot checked bag fee: ¥140 (pre-purchased online: ¥80-100)
- Recommendation: Pre-purchase checked allowance online saves 30-50% vs gate purchase
3.2 Weight Overages: Weighing Practices & Fees
AirAsia and Cebu Pacific commonly conduct random gate weigh-ins:
AirAsia Gate Enforcement (2025实测 data):
| Excess Level | Handling | Additional Cost |
|---|---|---|
| 7-10kg | Verbal warning, must lighten bag | Free |
| 10-14kg | Must check bag | ¥200-300/piece |
| 14kg+ | Must check + possible overweight surcharge | ¥300-500/piece |
When carry-on is overweight, remove essential items (valuables, lithium batteries, documents) into a personal pocket or waist pack—these typically aren’t counted in gate weighing.
3.3 Legitimate Weight Reduction Strategies
Strategy 1: Item Redistribution Transfer heavy items (laptop power adapter, spare batteries, extra clothing) to coat pockets or waist packs. Gate staff typically weigh only the main bag, not items worn or carried separately.
Strategy 2: Pre-Purchase Checked Bags Buy checked baggage on the airline website before departure, not at the counter. Spring Airlines: 10kg pre-purchased online ~¥80-120; counter price for same allowance ~¥140-200—a 40-70% premium for same service.
Strategy 3: Stroller Handling Families with strollers: most airlines gate-check strollers for free. This does NOT count against your regular checked baggage allowance. Policy varies—call ahead to confirm for your specific airline.
IV. Cross-Airline Comparison Summary Table
| Airline | Carry-On Pieces | Size Limit (cm) | Weight Limit | Free Checked |
|---|---|---|---|---|
| Spring Airlines | 1 piece (some fares: none) | 20×30×40 | 7kg | None (must buy) |
| 9 Air | 1 piece | 20×30×40 | 7kg | None |
| AirAsia | 1 piece (2 for premium cabins) | 56×36×23 | 7kg | Varies by fare |
| Ryanair | 1 piece (small) | 40×20×25 | None (informal ~7kg) | None |
| EasyJet | 1-2 pieces | 45×40×20 | ~10kg (practical) | None |
| Cebu Pacific | Varies by fare | Varies | 7-10kg | Some fares excluded |
| Jetstar | Varies by fare class | Varies | 7kg | Some fares excluded |
| West Air | 1 piece | 20×30×40 | 7kg | None |
| Xiang Air | 1 piece | 20×30×40 | 7kg | None |
| Tianjin Airlines | 1 piece | 20×30×40 | 7kg | Some routes included |
V. Smart Booking Strategies for Baggage
5.1 Calculate the True Cost of Fares with vs. without Baggage
For heavy packers, a “fare with baggage” sometimes beats “bare fare + separate bag purchase”:
Example using AirAsia:
- Bare fare: Shanghai–Kuala Lumpur ¥599/person
- Separate 15kg checked: ¥180/person
- Fare-with-baggage option: ¥799/person
Fare-with-baggage costs ¥200 more but includes 15kg checked. If you need more than 15kg, additional weight at ~¥12/kg means ¥200 already buys ~17kg—making the bundled option better value for heavy packers.
Rule of thumb: If fare-with-baggage ≤ bare fare + separate bag purchase, choose the bundled option.
5.2 Optimal Carry-On Packing (7kg Limit)
For the common 7kg carry-on limit, recommended distribution:
- Lightweight clothing: 30-40% of total weight
- Electronics (laptop + charger): 10-15%
- Toiletries (under 100ml bottles): 10%
- Documents + wallet + medication: 10%
- Miscellaneous: 25-30%
Valuables (cameras, jewelry, large amounts of cash) must remain in carry-on—never pack in checked luggage.
VI. Frequently Asked Questions
Q1: Will airports really penalize you for slightly overweight carry-on? A: Enforcement varies significantly by airline. AirAsia and Cebu Pacific conduct random gate weigh-ins with high probability—overweight bags must be checked on the spot. European carriers Ryanair and EasyJet enforce moderately. Spring Airlines is relatively lenient outside peak holiday periods. Safe practice: maintain 10-15% weight buffer below stated limits.
Q2: Do infants and children get extra free baggage on budget airlines? A: Most budget carriers offer little to no free baggage for infants under 2. Children aged 2-12 receive the same baggage allowances as adults. Families with infants should book fare-with-baggage options to avoid purchasing expensive last-minute checked allowances.
Q3: Can I bring two backpacks as carry-on? A: The vast majority of budget airlines permit only ONE piece of carry-on luggage. Premium cabin classes on some carriers allow two. A second backpack is treated as a second piece—requiring additional payment or checked bag handling. If you must carry two bags, ensure one meets the smaller under-seat dimension requirement (approximately 40×20×25cm) to avoid penalty.
Q4: Is Ryanair Priority Boarding worth buying? A: Following 2024-2026 policy changes, Priority Board’s primary value is the right to bring a large carry-on bag (55×40×20cm) into the cabin. Without Priority, regular passengers can only bring a small bag (40×20×25cm). At £6-15 for Priority vs £15-25 for a checked bag, Priority is better value if you have a regular-sized carry-on suitcase.
Q5: What are the lithium battery rules for carry-on? A: All lithium batteries (phones, laptops, cameras, power banks) MUST be in carry-on luggage—never in checked bags. Single battery rating: max 100Wh (unapproved); 100-160Wh requires airline approval; over 160Wh prohibited. Each passenger may carry up to 20 batteries under 100Wh. Consolidate all battery-powered devices in your carry-on, not checked luggage.
Q6: How small is Spring Airlines’ 20×30×40cm limit really? A: This is roughly the size of a school bag. Practically fits: 1-2 lightweight clothing items, one 500ml water bottle, one phone, a small wallet, and a few documents. Most adult backpacks (typically 35-40cm wide, 45-50cm tall) exceed this limit. Use a dedicated travel cabin bag (under 20 inches) or Spring Airlines-certified carry-on to avoid gate issues.
Want to turn travel into a career? Join Travel Arbitrage Partners