More than half of backpacks marketed as "carry-on" don't actually fit the strictest budget airline size restrictions, according to new data that analyzed 50 popular travel packs against Ryanair, EasyJet, Spirit, and US domestic carrier requirements.
The comprehensive comparison, shared on r/onebag, reveals that 52% of supposedly carry-on compliant bags fail Ryanair's 55×40×20cm sizer—including community favorites like the Osprey Farpoint 40, Peak Design 45L, GoRuck GR2, and Tortuga Pro 40L.
The failure point? Almost always depth.
Ryanair's baggage policy is among the strictest in the industry, enforcing the 20cm depth limit that many "carry-on" bags exceed by 2-5 centimeters. While some travelers report squeezing oversized bags through gate checks, the risk of forced check fees—currently €70 at the gate—makes compliance crucial for budget travelers.
But dimensional compliance tells only part of the story. The data uncovered massive weight disparities that directly impact packing capacity.
The GoRuck GR2 weighs 5 pounds empty. On Ryanair's 10kg (22 lbs) personal item limit, the bag alone consumes 23% of the weight allowance before a single item goes inside. By contrast, the Gossamer Gear Vagabond at 1.25 pounds uses just 5.7% of the allowance—a 17% difference in usable packing weight.
For travelers doing the math on what fits in a carry-on budget, that differential matters. An extra 3.75 pounds of capacity translates to several additional clothing items, toiletries, or tech gear.
Warranty coverage also varies wildly across similarly-priced bags. Bellroy charges $289 for bags with 3-year warranties. Tropicfeel asks $239 for 2-year coverage. Meanwhile, Osprey offers true lifetime guarantees on $200 bags. The value proposition appears inconsistent across the market.
Airline carry-on policies continue fragmenting, with budget carriers tightening restrictions while premium airlines maintain more generous allowances. The result: bags that work perfectly on Delta or United domestic flights fail European budget carriers entirely.
Several r/onebag community members confirmed the findings match their real-world experiences. One commenter noted successfully using a compliant 35L bag on 47 flights across Europe without a single size challenge, while another reported gate fees on an Osprey Farpoint despite its "carry-on" marketing.
The data builder is crowdsourcing corrections and additions to create an open dataset of accurate bag dimensions, actual weights, and real-world airline compliance.
For travelers committed to carry-on-only travel—the gold standard for avoiding baggage fees and saving time—the research suggests ignoring marketing claims and measuring bags against specific airline requirements. A bag that's technically 45L might measure within limits, while a 35L bag could exceed depth restrictions.
The best travel isn't about the destination—it's about what you learn along the way. And sometimes what you learn is that your favorite backpack won't actually fit under a Ryanair seat.
