Here is the lowdown on how airlines measure their seats.
SEAT PITCH
This is the distance between seats. broadly regarded as legroom. For fully-flat beds in business and first class, seat pitch is not really applicable, as there tends to be so much space between them that the only limiting factor is the length of the bed.
SEATS WITH A SMALL RECLINE
Recline is particularly important if you are hoping for a decent night's sleep. In economy class, airlines take the measurement in the following ways:
1 From horizontal to the furthermost recline.
2 From 90 degrees to the furthermost recline (given either in degrees or inches).
3 From the upright, take-off position to the furthermost recline.
SEATS WITH A LARGE RECLINE
In business and first class, the options for reclining seats are broadly cradle-style (CS), angled lie-flat (AF) and fully-flat (FF). Recline is measured in a number of ways. When it comes to angled lie-flat seats, it may sometimes be expressed as 180 degrees. the same as fully-flat beds.As this can be misleading, we have identified the seat types and exact angle of recline of each product. Meanwhile, beds of 176 degrees can feel like fully-flat beds, but are expressed as AF. In premium economy, some carriers have introduced fixed-shell (FS) seats that recline into a hard plastic surround, not into the space of the person behind you. \
SEAT WIDTH
Seat width is measured when the seat is fully upright, and is usually taken as the space between the armrests — so from the inside of one armrest to the inside of the other. It can also be the seat cushion width or even the distance between the outside of the armrests.
ENTERTAINMENT
As IFE systems become more sophisticated and are upgraded from simple multichannel offerings to interactive systems that allow for AVOD (audio-video on-demand), economy passengers often benefit from the same range of choice as in business or first class thanks to installation taking place throughout all cabins.