Companies like Ikea are selling beds in european sizes calling them king queen etc. if you buy a mattress of any indian brand for those same sizes, the mattress is either too big for the bed or small.
Imagine the consumer inconvinience to order something get it home pay cartage and then return it back to online or dealer on your own cost and fight to get a replacement which is also not of right size.
Please look into this standards body. more
Online shops does not give proper size as per their Adv. more