# A4, A5, A6, etc. is a GOOD paper size **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [June 21, 2006, 2:19pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574 "2006-06-21T14:19:18Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![patherto](https://avatars.discourse-cdn.com/v4/letter/p/ba8739/32.png) [@patherto](https://boards.straightdope.com/u/patherto)\ **Post date:** [June 21, 2006, 2:19pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/1 "2006-06-21T14:19:18Z")
I read Cecil’s explanation of why U.S. letter paper is 8.5x11 inches, after which he blew off metric paper sizes as “obsessive” and created by Germans. There’s one very handy thing about “A”-sized paper. (By the way, there’s “B”-sized papers as well. All “A”-sized paper has the same _proportions._ Thus, you can print a hardcover on, say, A3, and put out the paperback on A4 by simply blowing down the text. The layout remains constant. In the U.S. over the last decade or so, printers are finally starting to use the system the rest of the world relies on. This causes some problems, e.g. books too big for standard shelving, but the benefits far outweigh the hassles. “Obsessive”? No, smart. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [June 21, 2006, 3:07pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/2 "2006-06-21T15:07:04Z")
> [@patherto](#): > > “Obsessive”? No, smart. How about obsessive _and_ smart? (Just like the Germans. ;)) ---
**Author:** ![Khadaji](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Khadaji](https://boards.straightdope.com/u/Khadaji)\ **Post date:** [June 21, 2006, 3:25pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/3 "2006-06-21T15:25:21Z")
Hi patherto. A link to the column is usually considered polite. [Original](http://www.straightdope.com/classics/a3_016.html) ---
**Author:** ![hawthorne](https://avatars.discourse-cdn.com/v4/letter/h/c89c15/32.png) [@hawthorne](https://boards.straightdope.com/u/hawthorne)\ **Post date:** [June 21, 2006, 3:42pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/4 "2006-06-21T15:42:30Z")
A link to [Cecil’s column](http://www.straightdope.com/classics/a3_016.html) is useful when discussing old ones. And, yes, the A series has considerable charms. It looks beautiful and it can be scaled without waste. ---
**Author:** ![flodnak](https://avatars.discourse-cdn.com/v4/letter/f/838e76/32.png) [@flodnak](https://boards.straightdope.com/u/flodnak)\ **Post date:** [June 21, 2006, 8:19pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/5 "2006-06-21T20:19:21Z")
I edit a monthly club newsletter. It’s professionally printed up as an A5 booklet, but while I’m working on it at home, I can print it out on A4 sheets for proofreading with no waste or loss of proportions. Definitely a very logical system. But that doesn’t mean the whole A1-is-one-square-meter bit and some other details aren’t just a leeettle bit obsessive. ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [June 21, 2006, 8:54pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/6 "2006-06-21T20:54:25Z")
> [@flodnak](#): > > But that doesn’t mean the whole A1-is-one-square-meter bit and some other details aren’t just a leeettle bit obsessive. It’s actually A0 that is one square metre; A1 is 0.5 square metres; etc. And it’s like everything else in metric, it makes calculations easy. Say I have ream (500 sheets) of A4 paper, weighing 80 gsm (grams per square metre). How much does the ream weigh? Well, 500 sheets of A4 is 500/16 square metres, so the ream weighs 80\*500/16 grams, i.e. 2.5 Kg. (And one sheet weights 5 grams.) You can do it in your head. Try doing the equivalent calculation for US paper sizes. ---
**Author:** ![sinjin](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@sinjin](https://boards.straightdope.com/u/sinjin)\ **Post date:** [June 29, 2006, 11:01pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/7 "2006-06-29T23:01:51Z")
> [@Giles](#): > > It’s actually A0 that is one square metre; A1 is 0.5 square metres; etc. > > And it’s like everything else in metric, it makes calculations easy. Say I have ream (500 sheets) of A4 paper, weighing 80 gsm (grams per square metre). How much does the ream weigh? Well, 500 sheets of A4 is 500/16 square metres, so the ream weighs 80\*500/16 grams, i.e. 2.5 Kg. (And one sheet weights 5 grams.) You can do it in your head. Try doing the equivalent calculation for US paper sizes. It weighs 20 lbs. Jus like it says on the packet. I didn’t even have to use my head to figure that out… ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [June 30, 2006, 7:41am UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/8 "2006-06-30T07:41:47Z")
> [@sinjin](#): > > It weighs 20 lbs. Jus like it says on the packet. > > I didn’t even have to use my head to figure that out… Actually, [maybe not](http://en.wikipedia.org/wiki/Paper_size#.22Uncut.22_ream_basis_weight)… > [@Wikipedia](#): > > In countries using U.S. paper sizes, paper density is often specified in pounds. The stated mass is that of a ream of 500 sheets. However, the ream of that mass is normally not the one sold to the customer. Instead, the specified number of pounds is the mass of a “basis ream” in which the sheets have some larger size. ---
**Author:** ![Billdo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/billdo/32/315_2.png) [@Billdo](https://boards.straightdope.com/u/Billdo)\ **Post date:** [June 30, 2006, 11:36am UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/9 "2006-06-30T11:36:43Z")
> [@sinjin](#): > > It weighs 20 lbs. Jus like it says on the packet. > > I didn’t even have to use my head to figure that out… I think it is actually 5 lbs. The 20 lbs is the weight of 500 sheets of the standard 17" x 22" sheets described in the column. The 8-1/2 x 11 is one-quarter of the size of those sheets, so a ream of letter size is one-quarter of the pound weight of the paper. ---
**Author:** ![drhess](https://avatars.discourse-cdn.com/v4/letter/d/94ad74/32.png) [@drhess](https://boards.straightdope.com/u/drhess)\ **Post date:** [June 30, 2006, 12:51pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/10 "2006-06-30T12:51:49Z")
So what’s the story on B sized paper? ---
**Author:** ![Mops](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mops/32/16494_2.png) [@Mops](https://boards.straightdope.com/u/Mops)\ **Post date:** [June 30, 2006, 1:48pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/11 "2006-06-30T13:48:53Z")
B sizes for sheets of paper are very rarely used - generally B[number] is the size of a **large envelope** for A[number] sheets, and C[number] is the size of a **small envelope** for A[number] sheets. As a C-size is sufficient for all but the thickest stacks of A-size sheets C-size envelopes are much more usual than B-size envelopes. See the Wikipedia articles on [ISO 216](http://en.wikipedia.org/wiki/ISO_216) and [envelope sizes](http://en.wikipedia.org/wiki/Envelope_size). ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [June 30, 2006, 3:55pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/12 "2006-06-30T15:55:55Z")
> [@Billdo](#): > > I think it is actually 5 lbs. The 20 lbs is the weight of 500 sheets of the standard 17" x 22" sheets described in the column. The 8-1/2 x 11 is one-quarter of the size of those sheets, so a ream of letter size is one-quarter of the pound weight of the paper. Yes, 5 lb is much more consistent with the 2.5 kg for a ream of A4 paper. So, quickly, how much does a square foot of 20 lb standard American letter paper weigh? And how much does one sheet weigh in ounces? ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [June 30, 2006, 4:54pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/13 "2006-06-30T16:54:29Z")
> [@Giles](#): > > Yes, 5 lb is much more consistent with the 2.5 kg for a ream of A4 paper. > > So, quickly, how much does a square foot of 20 lb standard American letter paper weigh? And how much does one sheet weigh in ounces? One sheet = 1/500 ream = 5 lb / 500 = 80 oz / 500 = 0.16 oz. One sheet is 8.5" x 11" or 93.5 square inches. One square foot is 144 square inches, so it weighs 0.16 oz \* 144 / 93.5, or 0.2464 oz. It took me about 30 seconds to come up with that. Now, quickly, when would the average person need to make those calculations any more quickly? 😉 ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [June 30, 2006, 5:26pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/14 "2006-06-30T17:26:30Z")
> [@Giles](#): > > It’s actually A0 that is one square metre; A1 is 0.5 square metres; etc. Yep. And my new A0-sized laser printer is the talk of the office, let me tell you. Gets my memos _noticed._ Mind you, the refill cartridges are about to bankrupt me. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [July 7, 2006, 9:31pm UTC](https://boards.straightdope.com/t/a4-a5-a6-etc-is-a-good-paper-size/361574/15 "2006-07-07T21:31:12Z")
[An excellent overview of metric paper](http://www.cl.cam.ac.uk/~mgk25/iso-paper.html).