King mattress off by few inches

Hi all,
We just bought a King size mattress, and bed frame to go with it. Upon completion of assembly, we noticed the mattress was a few inches short of end of bed frame. I measured the mattress, and instead of a 76" x80" as it should be, it came out to 76"x77". Are new mattresses somewhat “compressed” and they need time to expand to their full size? Or did we just get jipped??? Please please PLEASE respond. I have anxiety and anyone with anxiety knows that it makes us latch on to completely unimportant things and makes it feel like this is the end of days.

Hi Kcx,

There are some comments about standard sizing and sizing variances in post #2 here that should be helpful.

It can take a few days or in a few cases even up to a week for a mattress to completely decompress and regain it’s correct size within a normal spec tolerance of +/- 1". While it won’t affect the comfort or support of the mattress … assuming that you’ve measured the mattress correctly and it’s still out of spec after that I would call the manufacturer or retailer you purchased from to let them know that your mattress is out of spec and they should be able to help you.

Phoenix