KLM Royal Dutch Airlines: will I fit?
Here is what KLM Royal Dutch Airlines does and doesn't publish about fitting comfortably on board, verified June 11, 2026 from the sources linked on this page.
Planning number: narrowest published economy seat
16.3″
Up to 18.1″ depending on aircraft and seat. We plan around the smallest figure the evidence supports: here's why.
- Seatbelt
- 42.1-61.0 in
- Extender
- Available: how to ask
- Second seat
- Extra seat ~75% of fare via customer service · full policy
Seat width
KLM does not publish classic 'seat width' specs, but its passenger-of-size page publishes the space between armrests per aircraft type: 41.5-46 cm (16.3-18.1 in) in Economy depending on aircraft.
| Aircraft | Economy width | Source |
|---|---|---|
| Airbus A330 | 18.1 in | per KLM Royal Dutch Airlines, pending our direct verification |
| Boeing 777 | 16.9 in | per KLM Royal Dutch Airlines, pending our direct verification |
| Boeing 787-9 | 16.9 in | per KLM Royal Dutch Airlines, pending our direct verification |
| Boeing 787-10 | 16.3 in | per KLM Royal Dutch Airlines, pending our direct verification |
| Boeing 737 (700/800/900) | 16.9 in | per KLM Royal Dutch Airlines, pending our direct verification |
| Embraer 175 / 190 / 195-E2 (KLM Cityhopper) | 17.7 in | per KLM Royal Dutch Airlines, pending our direct verification |
Verification notes (seat width)
Figures are KLM's published 'space between armrests' in Economy Class, converted from cm (A330: 46 cm; B777: 43 cm; B787-9: 43 cm; B787-10: 41.5 cm; B737: 43 cm; Embraer 175/190/195-E2: 45 cm). Premium Comfort is 48-50 cm. KLM's economy-class-seats page publishes legroom/recline only, not width. The passenger-of-size page does not yet list the incoming Airbus A350.
Seatbelt length
KLM publishes seat belt lengths on its passenger-of-size page: Economy Class belts are between 107 cm and 155 cm (approx. 42-61 in); Premium Comfort 124 cm; Business 124-148 cm. per KLM Royal Dutch Airlines, pending our direct verification
Verification notes (seatbelt)
Verified on klm.com on 2026-06-11: KLM still publishes belt lengths (in cm). The wide 107-155 cm Economy range means belt length varies considerably by aircraft/seat; KLM does not break it down further.
Seatbelt extender
Available. Ask the cabin crew on board; no pre-booking mechanism is described. The extender adds 63 cm (approx. 24.8 in) to the seat belt length.
Restrictions to know about:
- Personal seat belt extenders may not be used ('Because of safety, you cannot use your own seat belt extender').
- Extension belts cannot be used in exit row seats due to safety regulations.
Bring-your-own warning: KLM Royal Dutch Airlines requires you to use the extender its crew provides. Personal extenders are not permitted onboard.
per KLM Royal Dutch Airlines, pending our direct verification
Verification notes (extender)
KLM is unusually transparent: it publishes the exact added length of its extender (63 cm). No mention of inflatable/airbag-seatbelt seats on this page.
Second-seat policy: “Flying as a passenger of size (KLM's own page title); extra seat sold as an 'additional adjacent seat'”
KLM frames the extra seat as optional, not mandatory: 'For those who prefer more personal space, we offer the option to purchase an additional adjacent seat at a discounted rate.' The page also publishes armrest spacing and belt lengths so passengers can self-assess, and notes you need to be able to move your seat's armrests up and down. Separately, KLM sells check-in-time comfort products ('Empty Seat' to block adjacent seats, and 'My Extra Space' to block your whole row).
When a second seat applies
KLM does not publish a hard requirement; the additional seat is presented as a recommended option for those who prefer more personal space. No published criteria (e.g., armrest test) trigger a mandatory second seat.
How to arrange it
Contact KLM customer service to arrange an additional adjacent seat; cost is typically 75% of the fare of the original seat (prices may vary by route and class). The 'Empty Seat' / 'My Extra Space' blocking options are bought during online check-in, from 30 hours before departure, subject to availability.
Refunds
Not published for the customer-service-arranged additional seat. For the 'Empty Seat'/'My Extra Space' check-in products, KLM states you automatically get a refund if the seat is needed to accommodate other passengers or becomes unavailable for operational reasons.
per KLM Royal Dutch Airlines, pending our direct verification
Print the gate card: this policy, dated and sourced, on one page to hand calmly to an agent.
Verification notes (policy)
Empty Seat / My Extra Space details verified at https://www.klm.com/information/travel-class-extra-options/economy-class-seats (accessed 2026-06-11). The 75% discounted-rate figure is on the passenger-of-size page with the caveat 'prices may vary'.
What we could not verify
Honesty over completeness. These are the gaps we found and chose not to paper over:
- Refund conditions for the customer-service-purchased additional adjacent seat are not published on the passenger-of-size page; could not verify what happens if the flight oversells or the passenger cancels.
- KLM does not publish conventional cushion seat-width specs per aircraft, only 'space between armrests'; the two metrics are close but not identical.
- Incoming Airbus A350 not yet listed on KLM's passenger-of-size armrest table as of 2026-06-11.
- klm.com could not be read directly by automated tools; the live official pages were read indirectly on 2026-06-11.
Sources for this page
- Seat width, Airbus A330: https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Seat width, Boeing 777: https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Seat width, Boeing 787-9: https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Seat width, Boeing 787-10: https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Seat width, Boeing 737 (700/800/900): https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Seat width, Embraer 175 / 190 / 195-E2 (KLM Cityhopper): https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Seatbelt: https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Extender: https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)
- Second-seat policy: https://www.klm.com/information/assistance-health/passenger-of-size (per KLM Royal Dutch Airlines, pending our direct verification)