How do I know what size mat is needed for my door installation?

There are American National Standards Institute (ANSI) standards sponsored by the Builders Hardware Manufacturers Association (BHMA) that determined basic installation limits for each style of door. Standards are listed in ANSI/BHMA A156.10.

You will need to know the clear opening of the door (72" etc.), what type of door (swing, slide, bi-fold) and if the installation is to accommodate two way traffic (traffic in both directions).

Check with your local building inspector to ensure there are no local building codes that supercede those listed in the ANSI/BHMA Standards.