Seat letters decoded: which letter is the left window?
You've worked out which side of the plane you want - say, the right side for the Alps. You open the airline's seat map and it offers you 23A, 23F, 23K. Which letter is the right-hand window? Get this wrong and all the sun-and-scenery homework buys you a view of the wrong horizon. The conventions are simple, but the exceptions are worth knowing.
The rule: A is always left
Seat letters run from the left side of the aircraft, facing forward - the same convention as the captain sitting on the left. Seat A is the left window on essentially every airline in the world. "Left" here means the aircraft's left as it flies, which is your left when seated facing the cockpit. So when a verdict on this site says left, that's the A side; right is the highest letter in the row.
Narrow-body aircraft: A and F
A320s, 737s and other single-aisle jets in a 3-3 layout letter their seats A-B-C (left trio) and D-E-F (right trio). A = left window, F = right window, C and D are the aisles. In a 2-2 regional layout it's usually A-C and D-F, keeping A and F as the windows even though there's no B or E. Embraer E-Jets (2-2) letter A-C / D-F on most carriers too.
Wide-body aircraft: A and K
Twin-aisle jets skip letters so that the same letter means roughly the same position across the fleet. A common 3-3-3 economy layout (777, A350) runs A-B-C / D-E-F(G) / H-J-K: A = left window, K = right window. The letter I is skipped almost universally (it reads as a 1), and B or E may vanish in business cabins with fewer seats per row. The practical takeaway: on a wide-body, book A for left views and K for right views, and treat F as a middle-section seat, not a window.
Exceptions worth checking
- Windowless window seats: most types have a row where ducting replaces the window (often around rows 10–12 on A320s, varies by airline). The seat letter is right; the window is missing. Check a seat-map site for your exact airline + type.
- Misaligned windows: seat pitch and window spacing don't match, so some rows get a window half behind the seatback. Fine for glancing, annoying for photography.
- Business/first quirks: staggered and herringbone layouts mean not every A or K seat faces its window squarely, and some "window" positions are a full seat-width from the glass.
- Equipment swaps: if the airline changes aircraft type, letters can reshuffle (F flips from window to middle when a narrow-body becomes a wide-body). Re-check your seat after any schedule-change email.
Booking the side you want, quickly
The workflow that works: first get the side verdict for your route and date (run it here - left, right, or split by phase). Then on the seat map, translate: left → A; right → F on a single-aisle, K on a twin-aisle. Then sanity-check the specific row for missing/misaligned windows and wing position - our window-seat guide covers the row strategy. Total extra effort: about two minutes, once per trip.
More guides
- How to pick the perfect window seat: the complete guide
- Left or right? The simple geometry that decides your view
- Chasing sunrise and sunset from a plane window
- How to avoid sun glare on a flight (and why it matters)
Or just check your own flight - enter a route, date and departure time and get a left/right verdict in a second.