Paper sizes explained | Number Hub with Matt Parker | Head Squeeze

Have you ever wondered why A4 is the way it is? Well Matt Parker has sorted it all out for you.

Two A4's side by side make an A3. Two A3's side by side make an A2. Two A2's together make an A1 and two A1's together make a A0. Almost like magic isn't it? Well it isn't. As Matt Parker explains the A4 paper scale is based on a meter and one meter is exactly one forty millionth of the circumference of the earth.

How does that compare to the US paper sizes? Well you have ledger which is seventeen inches by eleven inches. And then there is tabloid which is eleven inches by seventeen inches. (Are you beginning to see the similarities as well?) Then there is legal which is eight and a half inches by fourteen inches, and Junior legal which is eight inches by five inches.

Are you metric or imperial? Let us know in the comments below!

[BBCEarthScience]

Matt is right, A0 is one meter squared in area, but we got the graphics wrong!

The A0 dimensions are 1189 X 841 mm or 46.8 X 33.1 inches!

[marcosdiez]

The video misses one of the most important features of the A4 system: paper weight. If you have to send a (physical) document made of several sheets of paper by mail, you'll be charged by weight. How to make a budget for that, or how to choose paper for that? With A4 system it's a piece of cake: paper is being sold with a known weight in grams (again, metrical system) for each A0 sheet (square meter), so let's say, a "80 g/m2" paper means that an A4 sheet weights exactly 80/16 = 5 grams, the your 250 pages document will weight 1, 25 kg without need of a balance at hand, and if you want it to weight less than a kilogram, then you do the opposite to find out you have to buy A4 sheets of 64 g/m2 or less. To do the same with the imperial measure, well... you better start googling it.

And you even have a correlated envelopes measuring system, called the "B" system.

[veilside]

"Junior Legal: That's what you use when you're suing a child." Totally lost it at this point. Love your work mate.

[FranzReischl]

As a technician, I have to admit: I *love* the A4 scale. It´s convinient, logical, predictable. The best part for technical drawings: if you scale it down two A sizes, you end up with a legit ratio again - every distance on the paper is then just half the original size.

[andrewmoschou]

One of the beauties comes in technical drawings. Pen sizes come in 1mm, 0.7mm, 0.5mm, 0.35mm, 0.25mm. So if you're drawing on A3 in 0.7mm, you can photocopy and scale it down to A4 and then continue drawing in 0.5mm and the lines will still have the same thickness.

[IAMMRAMAZING]

I'm not sure but I think he might not like the American paper system

[henk]

1:00 A0 is equal to one square meter, but of course it's not 1 meter by 1 meter :)

[rulerandstapler]

"you don't get a different sized paper by rotating it slightly" 😂😂

[alandouglas]

I laughed so hard when Matt said "doesn't sound like freedom to me"

[ArndBergmann]

It's also particularly convenient to have 80g/m^2 paper as the most common type for printer paper, as that makes one sheet of A4 have a mass of exactly 5.000g.

If you ever want to know how many sheets of paper you have in a stack, just weigh it.
Since a regular DL or C6 envelope is made from roughly one sheet of A4 paper, and letters (at least in Germany) can weigh up to 20g or 50g depending on the stamp you use, that also means you can send letters with up to 3 or 9 pages and don't need a scale to know what stamp to use.

[TheConnor]

"The only rational irrational choice when it comes to paper sizes" is a fantastic line!

[TCWordz]

"Doesn't sound like freedom to me!"

[guerra_dos_bichos]

that's wat you use when you are sueing a child.

[TheRealFOSFOR]

5:10 "If you are suing someone." .. Gimme a break. This is the US we are talking about. You should have said "When you are suing someone."

[TristanBomber]

The drawing for A0 is inaccurate. It's not a square, it's a ratio of 2 to sqrt(2), just like every A# paper.

[KishoreShenoy]

Do you think the Audi A1 is twice the size of the Audi A2?

[tynoArcher]

"someone really has pulled that out of their ASSumption" Ahahahha very slick Matt >.<

[thrango]

As an American, I support A4 and the measurement of meters(metres? One step at a time). But not everyone is so open-minded.

[Nixitur]

Being able to half A4 to make two A5's is so incredibly useful when you're printing stuff and don't want to waste paper. After all, in a lot of cases, especially when what you're printing out is a projector presentation, you don't need the full font size to read it clearly. Being able to easily fit 2, 4 or even 8 pages on one side of paper is just so handy.

[mlangley]

The Meter was originally supposed to be 1/10, 000, 000 if the distance from the North Pole to the Equator. It was painstakingly measured out by hand from the North of France to the Spanish Mediterranean over many years spanning the time of the French Revolution, (which complicated matters). At that time it was thought the Earth was a perect sphere. What is truly remarkable is how close they got. There is a book called "The Measure of All Things" which is really quite fascinating.