Differences Between Legal Size Paper and A4 Size Paper

Human civilization owes much of its progress to the invention of paper. From writing on cave walls to stones to metal sheets to papers, the evolution of writing media has become synonymous with the evolution of human civilization. But, nowadays you can’t just write anything on any kind of paper.

A4 vs Legal Size Paper

Legal-size papers are primarily used in North American countries like the USA and Canada for legal documentation.  On the other hand, A4 paper is used worldwide for various uses ranging from writing letters to magazines.

If you are still unsure about what paper sizes to use and for what purpose, let’s take a look at a comparative analysis of legal size paper vs A4 paper in order to help you make up your mind. While we are at it, we will also look at one or two other kinds of paper sizes so that you don’t get confused.

What Are Legal And A4 Size Papers

Before we can get into the debate of legal size paper vs A4 paper, we have to gain a bit of knowledge about both paper sizes and the international paper size system. This will help us in the long run.

The A4 paper is a size adopted as a standard for typing by the International Standards Organization which is more commonly known as ISO. It became a standard size in the 1970s, although it was proposed by Dr. Porstmann of Germany that all papers have a standard size.

Legal-size papers are almost exclusively used in North America, although some documents of the UK and other commonwealth countries are also written on them. While the A4 papers are formalized by ISO standard, the legal paper sizes have been formalized by the ANSI Y14.1M – Metric Drawing Sheet Size & Format.

From the size to their uses, there are a lot, and I do mean a lot of differences between legal size papers and A4 papers. Let’s take a look at those differences one by one.

Paper dimensions and sizes

Paper dimensions and sizes

The legal paper that is used in Canada is 8.5 inches or 216 mm wide and 11  inches or 279 mm long. But, the ones that the Americans use are a bit different, especially in their length. The US version of the legal paper is 8.5 inches or 216 mm wide with a length of 14 inches or 356 mm. They have an area of about 0.077 sq.m.

As the A4 paper is of international standard, they do not vary in size with respect to the country they are being used in, like the legal paper. They have a fixed size width of 8.3 inches or 210 mm and 11.7 inches or 297mm in length. So, they have an area of 0.062 sq.m.

So, the US legal papers are longer in size than both their Canadian counterparts and A4 papers.  Also, they cover more area than the A4 papers do.

Aspect Ratios

Aspect Ratios of legal size paper vs a4

The legal size papers follow an aspect ratio of 1:1.6471. Although they follow this aspect ratio,while they are sized, it is not done keeping any size in mind.

The A4 papers have an aspect ratio of 1:1.4142. They are sized keeping a 1:√2 (Square  root of 2) proportion in mind.

Difference in Areas of Use

Even the areas that these two kinds of papers are used are not the same. Legal size papers are basically used in North America only. That means the USA, Canada, and part of Mexico use legal size papers for legal purposes.

On the other hand, A4 is an international standard-sized paper. So it is used almost all over the world from Australia to Venezuela and from New Zealand to China.


uses of a4 size paper and legal size paper

Apart from the size, the biggest difference between the legal size paper and A4 paper is their field of use.

Lawyers and legal representatives prefer legal size paper to document legal matters. This is because of the length of the paper. As we have seen earlier, the legal size paper is longer than the A4 paper.

This helps in writing contracts which can be quite lengthy. Although they are mostly used by lawyers, that does not mean that they are the only people who use them. Accounting farms, banks, real estates, and sometimes even hotels use legal size papers.

If you want to print a spreadsheet, it is the perfect choice to do so because it is longer and also covers more areas which is ideal for longer documents. Even restaurants have taken a liking to this somewhat ancient-sized paper as it allows them to print their menu or even replace it when the need arises as they are quite cheap.

A4 papers are the go-to paper for printers. Because of this, its usage varies from letter writing paper to school notepads and forms. Children’s books are also printed on this paper. Encyclopedias, which require a bit more space for illustration purposes, also use A4.

Do you need to print a magazine? Use A4 paper. Want to print leaflets? Use A4 paper for these as well. As unbelievable as it sounds, the leaflets that we see nowadays are actually A4 papers that are folded in three.

You can also use them for your everyday use. Students can use A4 papers for writing stuff from homework to assignments to applications to the authorities. You can even write a grocery list on an A4 paper.

So, we can see a pattern here. While legal size papers are used for making legal documents primarily, A4 papers are the go-to choice for printing stuff, no matter what they are, except for spreadsheets and also, day to day usage.

Difference in Problems Created

Legal size papers and A4 papers are also different in the problems they tend to create. If you are using an office printer, printing on a legal size paper can be a pain in the rear. Due to their large size, most office printers can not load them. Also, you can not use legal size papers in everyday use.

They can only be used for official and legal purposes. For example: If you are in urgent need of a paper to write an application of any kind and only have legal size paper at hand, you have to go buy an A4 paper because you can not write an application on legal size paper.

Due to the international standardization of the A4 paper, it causes fewer problems. But if you are living in the US, you will need the legal size paper for legal procedures. You can not use A4 papers for this purpose in the US. Also, while printing spreadsheets, if you use A4 papers, you will know pain like nothing else as it has a smaller area.

Legal Paper Size vs. Letter Paper Size

One of the biggest confusions that people suffer from is choosing between legal size[8.5×14″] and letter size papers [8.5″x11″]. While they have the same width, the letter size paper specially made for letter format is 3 inches shorter than the legal size paper.

From a 17″ x 22″ sheet, you can make two letter sized papers, but only one legal sized paper. So letter paper sizes are more economically viable.

As a result, they are becoming more and more common.

Other Sizes of Papers

The Legal size and A4 are not the only two sizes of paper that are available. There are plenty of other sizes of papers that are still in use today, both ancient and modern.

Foolscap Paper

This was the traditional paper that was used for everyday purposes until the advent of A4 papers. They are 8.5 inches or 216 mm in width and 13.5 inches or 343 mm in length. They had an aspect ratio of 1:1.5879. We can see they are considerably larger than the currently used A4 papers.

Letter Size Paper

Letter size papers are also often referred to as ANSI sizes or ANSI letter size papers. They are of similar dimension to those of A4 papers, 8.5 inches or 216 mm in width and 11 inches or 279 mm in length.

The A-Series Paper Size

The A Series Paper sizes

Upon seeing the name A4, you might ask yourself whether there are other papers such as A1, A2 that exist or not. The answer is, yes. The A4 is a member of the A-series sheets, which have papers from A0 to A10 sizes.

A0 papers are humongous in size with the dimensions of 33.1 x 46.8 inches and are used for technical drawings while the smallest of them, A10 has dimensions of only 1.0 x 1.5 inches and are used to make stamps and small vouchers. There is a whole range of uses, from making posters to printing tickets.

The B Series Paper

B series paper

The A-series is not the only alphabetically named series. The B series comprises B0+, which is the largest of all the papers of the B series to the B13, which is the smallest with only 11 x 15 mm dimensions.

Compared to the A-series, they are less commonly used in offices, but they are used in posters, envelopes, and books more often.

The C Series Paper

C series paper

The C series is the third and last size of paper which is named after an alphabet.  Their dimensions are also defined by the ISO, this time by 269 standards. Most commonly help in making envelope formats, their area is unique.

They have papers from the largest C0 to the smallest C10.

Frequently Asked Questions

#1. Is legal paper A5?

No,the legal size is longer than A4  and covers more area. On the other hand,A5 is smaller than A4. So legal paper is way bigger than A5.

#2. What size is legal paper?

Legal papers are 8.5 inches wide and 14 inches long. They have an area of 0.077 sq. m [22cm x 36cm].

#3. How do I copy a legal size paper to A4?

You can only copy legal size paper using the ADF. First, you have to clear the platen glass of any documents. Then, after opening the document tray, load the document in ADF.

Then turn on the machine and press copy. After that,zoom in or out of the document and press ’Copy’.  After doing that,select the number of copies and select the type of copy, coloured or black and white.


From the most commonly used A4 to the almost forgotten legal size, papers are a part of our day-to-day lives. No matter how much the letter size replaces the legal size or how much A4 is being used, there are certain uses for certain papers that can not be acquired by any other papers.

If there’s one thing that can be learned from the above comparative analysis of legal size paper vs A4 paper, is that we must know the different uses of papers and use them accordingly.