Hello @wordpress112233
Assuming you have two fields for the width and length of the room (fieldname1 and fieldanme2), and a dropdown field with the list of tiles whose choices’ values are their corresponding areas (fieldname3). The equation to calculate the number of tiles required to cover the room area can be implemented as follows:
CEIL(fieldname1*fieldname2/fieldname3)
The CEIL operation rounds the result to the next integer number.
Best regards.