Hard portfolio paper size standard???

I have recently moved to the New England area from the Uk and am having problems in finding the de facto standard in paper size for a standard US hard portfolio.

The UK would normally use A3 (11.7" x 16.5" approx) or A2 (2 x A3). Is there a standad in the US?

Any advice would be greatly appreciated

I would go with either 8.5" X 11" which is Letter size, or 11" X 14". I had mine in 11" X 14" for the longest time, but decided digital was definitely the easiest format to send to people quick and cheap.

how much money and work do you want to put into it?

go with a standard size, letter or tabloid, if you want to shoot off color prints quickly. or create a non-standard size that seems interesting to you (square, panoramic) or suits your identity. just be prepared to spends some time trimming and doing custom punching (screwposts are pretty freely available) or binding (if you can or want to).