Door measurement question

[richrc1131]

I realize this may be a very basic question, but I'm new to all of this.

I finally fixed an exterior doorway that had a screen door in it at some point ( there were marks where door hinges must have gone).

I now need to install a screen door. I looked at stock at Lowes and Home Depot and found that they had 30" doors. I measured the doorway I'm trying to complete and it is 29.5"

Are those measurements rounded off like the way a 2"x4" is?

[jadnashua]

The thing to look at is the rough opening the thing is designed to fit in.

[jimbo]

Screen doors come in standard sizes....30, 36, with 32 and 34 less common. Virtually all screen doors you will find in a home store have and adjustable width, within a range, so they can be installed to fit your particular trim. A 30" door should work for you.

[hj]

IF there is a door in the doorway, then it is a 30" door, since they do NOT make 29 1/2" doors.

[cacher_chick]

If there are hinge marks on the existing frame, the old door was a wood screen door. Aluminum/vinyl screen doors are pre-hung.