📑 Table of Contents ▾
Part 1: How Budget Airline Baggage Policies Actually Work
💡 Cheap-flight search: Kiwi.com often beats official airline pricing by 15–25% thanks to cross-carrier itineraries unavailable elsewhere.
Low-cost carriers (LCCs) keep ticket prices low by stripping out bundled services and selling extras à la carte. Carry-on baggage policy is one of the most central — and most confusing — elements of this model, and it’s also where passengers most often get caught out.
Understanding the logic helps you make the right call at the airport. Full-service carriers (like major legacy airlines) typically include free checked baggage and two carry-on pieces. Budget airlines, by contrast, usually restrict cabin baggage to a single piece of 7–10 kg, and anything beyond that must be purchased separately.
Why do budget airlines restrict baggage so tightly? The core reason is cost control. Fuel burn is directly tied to weight. Every additional kilogram of baggage requires roughly 0.03–0.05 liters of extra fuel. On a 180-seat A320, if every passenger carries 5 extra kilograms, the total extra fuel load is 27–45 kg — which, at current fuel prices, adds $16–27 per flight. Across 10,000 flights a year, that’s $160,000–$270,000 in additional fuel costs.
Weight also affects load distribution. Carry-on bags concentrate in the overhead bins at the front of the cabin; if total weight exceeds the design threshold, it can shift the aircraft’s center of gravity and affect flight safety. Budget carriers use strict weight limits to maintain precise load balancing and keep operating costs down.
Part 2: 2026 Carry-On Allowance Comparison Across 10 Airlines
2.1 Asian Budget Airlines
Spring Airlines Spring Airlines is China’s largest low-cost carrier, operating primarily on international routes to Japan, South Korea, and Thailand, as well as some domestic services. Its carry-on policy is the most restrictive in the market:
| Fare Class | Carry-On | Size Limit | Weight Limit | Oversize Handling |
|---|---|---|---|---|
| Promo Fare | No free carry-on | — | — | Must purchase |
| Value Fare | 1 piece | 20×30×40 cm | 7 kg | ¥140/piece |
| Comfort Fare | 1 piece | 20×30×40 cm | 7 kg | ¥140/piece |
| Premium Fare | 1 piece | 20×30×40 cm | 7 kg | ¥140/piece |
Spring Airlines’ 20×30×40 cm size limit is significantly smaller than the 20×40×55 cm standard used by most other carriers. A typical laptop backpack (usually 20×35×45 cm) will likely exceed this limit — worth noting before you pack.
9 Air (Juneyao’s LCC) 9 Air is affiliated with Juneyao Airlines, based in Guangzhou and Guiyang, and focuses on domestic and Southeast Asian routes. Carry-on policy:
- Free carry-on: 1 piece, 20×30×40 cm, 7 kg
- Oversize handling: purchase checked baggage allowance (minimum 10 kg, approximately $11–20)
- Note: Some 9 Air fares are “bare fares” that don’t include even carry-on baggage
West Air West Air is based in Chongqing and Zhengzhou, focused on domestic budget routes. Its carry-on policy mirrors 9 Air: 1 piece, up to 7 kg, 20×30×40 cm. Checked baggage must be purchased separately — 10 kg starts from approximately $14.
2.2 International Budget Airlines
AirAsia AirAsia is Southeast Asia’s largest low-cost carrier and operates direct routes from multiple Chinese cities.
| Fare Type | Carry-On | Size Limit | Weight Limit |
|---|---|---|---|
| Standard | 1 piece | 56×36×23 cm (~7 kg) | 7 kg |
| Premium Flatbed | 2 pieces | Same as above | 7 kg × 2 |
AirAsia’s size allowance (56×36×23 cm) is considerably more generous than Spring Airlines and is roughly equivalent to a standard cabin-size trolley bag. However, the 7 kg weight limit is still strict by global standards, and AirAsia is known for enforcing it at the gate.
Ryanair Europe’s largest low-cost carrier, notorious for its strict baggage policy.
- Small carry-on: 40×20×25 cm, fits under the seat in front (free)
- Large carry-on: 55×40×20 cm, must go in overhead bin (requires priority boarding purchase, or pay a fee)
- Tightened since 2024: only passengers with Priority Boarding may bring a full-size carry-on bag onto the aircraft
Ryanair’s rules are complex and change frequently. As of 2025–2026: standard-fare passengers may only bring the small 40×20×25 cm bag for free. Anything larger requires purchasing Priority Boarding or paying a baggage fee. Passengers are routinely asked at the boarding gate to check oversized bags — and pay 2–3x the standard baggage rate on the spot.
EasyJet The UK’s largest budget airline, with relatively lenient carry-on rules:
- Free carry-on: 1 piece, 45×40×20 cm, no official weight limit stated (in practice, approximately 10 kg is enforced)
- Additional carry-on: available for purchase on the website at £6–15/piece
EasyJet does not weigh carry-on bags at check-in, but cabin crew can require passengers to check bags that are visibly overweight.
Cebu Pacific Philippines-based LCC, commonly used on Southeast Asian routes:
- Base fare: does not include carry-on baggage; must be purchased separately
- Fare with baggage: 1 carry-on piece, size and weight vary by route, approximately 7–10 kg
Cebu Pacific promotional fares typically include no baggage at all — read the fare conditions carefully when booking.
Jetstar Australian and Southeast Asian low-cost carrier:
- Starter fare: no carry-on included
- Starter Plus fare: 1 carry-on piece up to 7 kg
- Jetsmart: Thailand domestic routes include 1 free 7 kg carry-on
Part 3: Common Oversize/Overweight Scenarios and Solutions
3.1 Size Violations: Real Gate-Check Cases
The most common scenario is a backpack that exceeds the 20×30×40 cm limit. Using a typical laptop backpack (20×35×45 cm) on a Spring Airlines flight as an example:
Real case (March 2026, Shanghai Hongqiao to Osaka):
- Backpack actual size: 20×35×45 cm
- Spring Airlines requirement: 20×30×40 cm
- Outcome: passenger required to check the bag
- On-the-spot checked baggage fee: ¥140/piece (pre-purchase on website: ¥80–100)
- Takeaway: purchasing checked baggage in advance is 30–50% cheaper than paying at the airport
3.2 Weight Violations: On-the-Spot Weighing and Fees
Some airlines (AirAsia in particular) set up weight check points at the boarding gate for random carry-on weighing.
AirAsia gate weighing procedures (based on 2025 real-world data):
| Excess Weight | Action | Extra Fee |
|---|---|---|
| 7–10 kg | Verbal warning, asked to redistribute | Free |
| 10–14 kg | Must check the bag | $27–40/piece |
| 14 kg+ | Must check + possible excess weight surcharge | $40–67/piece |
If your carry-on is overweight, immediately remove essentials (valuables, lithium batteries, documents) and transfer them to a smaller personal item before checking the rest.
3.3 Legal Redistribution Tricks to Avoid Overweight Fees
Smart packing choices can meaningfully reduce overweight risk without compromising your trip:
Trick 1: Wear the heavy stuff Move heavy items from your carry-on — laptop power adapters, spare power banks, extra clothing — into jacket pockets or a waist pack. These items typically won’t be weighed as part of your carry-on.
Trick 2: Pre-purchase checked baggage online Buy checked baggage allowance on the airline’s website before you travel rather than paying at the airport. Spring Airlines’ online rate for 10 kg runs ¥80–120; at the airport counter, the same allowance costs ¥140–200 — a 40–70% premium.
Trick 3: Strollers gate-check free Families traveling with strollers can typically check them at the boarding gate for free, and strollers don’t count toward standard checked baggage allowances. This policy varies by airline — confirm with your carrier before departure.
Part 4: Quick-Reference Baggage Policy Comparison Table
| Airline | Carry-On Pieces | Size Limit (cm) | Weight Limit | Free Checked Baggage |
|---|---|---|---|---|
| Spring Airlines | 1 (some fares: none) | 20×30×40 | 7 kg | None (must purchase) |
| 9 Air | 1 | 20×30×40 | 7 kg | None |
| AirAsia | 1 (Premium: 2) | 56×36×23 | 7 kg | Some fares exclude |
| Ryanair | 1 (small only) | 40×20×25 | No stated limit | None |
| EasyJet | 1–2 | 45×40×20 | ~10 kg | None |
| Cebu Pacific | Varies by fare | Varies | 7–10 kg | Some fares exclude |
| Jetstar | Varies by fare level | Varies | 7 kg | Some fares exclude |
| West Air | 1 | 20×30×40 | 7 kg | None |
| Loong Air | 1 | 20×30×40 | 7 kg | None |
| Tianjin Airlines | 1 | 20×30×40 | 7 kg | Some routes include |
Part 5: Baggage Strategy When Booking
5.1 Choosing the Best Ticket Type for Your Luggage
For passengers traveling with more luggage, a “with baggage” fare can sometimes be cheaper than a bare fare plus separately purchased checked baggage. Using AirAsia as an example:
- Bare fare (Shanghai–Kuala Lumpur): $82/person
- Separately purchased checked baggage (15 kg): $25/person
- With-baggage fare: $109/person
The with-baggage fare is $27 more, but includes 15 kg. If your checked baggage exceeds 15 kg, extra kilograms cost approximately $1.65/kg — meaning the with-baggage fare is already better value before you factor in overage. The formula: if (with-baggage fare) ≤ (bare fare + purchased allowance), the bundled fare wins.
5.2 Packing Optimization for 7 kg Carry-On Limits
For a 7 kg carry-on, here’s a practical weight distribution guide:
- Clothing (lightweight): 30–40% of total
- Electronics (laptop + charger): 10–15%
- Toiletries (100 ml containers): 10%
- Documents + wallet + medications: 10%
- Miscellaneous: 25–30%
Valuables (camera, jewelry, large amounts of cash) should stay in your carry-on, not go into checked bags. Lithium batteries and power banks (under 100 Wh) must be in carry-on and cannot be checked.
Part 6: FAQ
Q1: If my bag is just slightly overweight, will they actually fine me? A: Enforcement varies significantly by airline. AirAsia and Cebu Pacific have a higher frequency of random gate weighing in Southeast Asia — if you’re over, you’ll be checked at the gate, full stop. Ryanair and EasyJet in Europe enforce at a moderate level. For Spring Airlines, enforcement is relatively relaxed but increases noticeably during peak holiday travel. The safe approach: leave a 10–15% weight buffer.
Q2: Do infants and children get extra free baggage allowance on budget airlines? A: Most LCCs provide no free baggage for infants under 2, or very limited checked allowance. Children aged 2–12 usually receive the same allowance as adults. If you’re traveling with a baby, book a fare that includes checked baggage rather than scrambling to buy it at peak last-minute prices.
Q3: Can I bring two backpacks on board? A: The vast majority of budget airlines only allow one carry-on item. Some premium fare classes permit two. A second backpack is treated as a second carry-on piece and will incur extra charges or need to be checked. If you must carry two items, make sure the second one is small enough to fit under the seat in front of you (roughly 40×20×25 cm), which typically escapes scrutiny.
Q4: Is Ryanair’s Priority Boarding worth buying? A: After Ryanair’s 2024–2026 policy updates, Priority Boarding’s primary value is the ability to bring a full-size cabin bag (55×40×20 cm) on board — not just queue priority. Without it, standard passengers can only bring the small 40×20×25 cm free item. Priority Boarding at £6–15 vs a gate baggage fee of £15–25 — Priority Boarding is the better deal.
Q5: Are there special rules for lithium batteries in carry-on bags? A: Lithium batteries (phones, laptops, cameras, power banks) must travel in carry-on baggage — they cannot be checked. Individual lithium batteries must not exceed 100 Wh; batteries rated 100–160 Wh require airline approval; anything above 160 Wh is prohibited. Each passenger may carry a maximum of 20 batteries under 100 Wh. Keep all battery-powered devices in your carry-on.
Q6: Just how small is Spring Airlines’ 20×30×40 cm limit? A: It’s roughly the size of a school backpack. In real-world terms, it fits: 1–2 lightweight clothing items, a 500 ml water bottle, a phone, a slim wallet, and some documents. Most adult everyday backpacks (typically 35–40 cm wide × 45–50 cm tall) exceed this limit. If you’re flying Spring Airlines, use a purpose-built cabin luggage bag under 20 inches, or pack in an officially compliant Spring Airlines cabin bag.
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