Does First Class allow larger sizes before hitting dimensional weight?

[pvcliff]

Cleaning up my desk and found a note I'd written from several weeks ago. Don't recall where I came across this information, but my note says "up to 16oz with dimensions 22x18x15 is under USPS first class package on label page" (so maybe I saw it myself on the label page).  Is this correct? Can low weight items that would qualify for FC be larger than 12x12x12/1728 square inches?

[nobody*s_perfect]

Yes they can, although a box that size might approach the weight limit even when empty.  Dimensional weight is not applied to First Class packages, at all.  It only applies to Priority Mail, Parcel Select Ground, and Retail Ground.

The DMM section about online First Class package dimensions is consistent with your note to yourself.

https://pe.usps.com/text/dmm300/201.htm#ep1097318