In the United States and neighboring countries like Canada or Mexico, we are used to writing on papers that come in letter sizes. The dimension of letter size paper is 8.5 inches by 11 inches.

However, when you step outside the country, especially in Europe and Asia, the sizing of papers is completely different.

The rest of the world uses what we call the International Organization for Standardization or ISO, for short, in determining a standard for different sizes of paper.

Though the system might feel a bit confusing at first, especially for those living in the states, once you get to know about it, it is actually quite simple.

Understanding the different paper sizes according to ISO can help you out when you are buying a notebook or starting to write a journal. That way, you will be able to find the perfect paper size for your purpose.

In this article, we will give you a complete rundown of understanding different paper sizes and give you an in-depth comparison between B5 vs A4 vs A5 sizes of paper. So, without further ado, let us get started.

## Understanding International Paper Size Standards

It is mostly North America that sticks to letter sizes. However, when you look elsewhere in the world, paper sizes are generally categorized into A and B.

You can also find C sizes, but since those are mostly for envelopes, we will not bother too much about them.

And between A and B sizes, A size papers are used more commonly. Let us start off this article with a basic understanding of the two major sizes used in the world, A and B.

### A Series Paper Sizes

As we have said just now, the A series is the more popular one of the two major variants. It was introduced originally by Germany around the twenties, and it quickly generated popularity all over Europe.

By the seventies, the whole world started using A size papers. Later on, it was accepted and adopted by the International Organization for Standardization.

The largest paper in the A series of size is the A0. Its dimensions are 84.1 cm by 118.9 cm which in USA standards would be 33.1 inches by 46.8 inches.

From here, to get to A1 size paper, you will take the total size of the A0 paper and cut it into half. So, the size of the paper is in exactly the same proportions but has half of the total surface area.

The fun thing about this sizing method is actually quite mathematical. Typically, if you cut a paper in half, the proportions of the two parts would be different from the original one.

However, because of the size of the paper and its aspect ratio of 1 to the square root of 2, cutting it in half gives you two exactly proportionate halves.

This phenomenon is what makes this system work so effectively. As long as the aspect ratio of a piece of paper is 1:1.4 (which is the square root of 2), the two halves would be equal in proportions.

There are a total of 19 different variations of A series of sizes. To get the next size A2, you have to cut A1 paper into half.

### What Is A4 Paper?

A4 papers have a dimension of 8.3 inches by 11.7 inches. This is the closest size to the standard letter size used in the USA. The total writing surface you get with an A4 size paper is 96.7 square inches.

### What Is A5 Paper?

A5 size paper is half the size of A4 paper. Its exact dimensions are 5.8 inches by 8.4 inches and give you a total writing surface of 48.2 square inches.

### B Series Paper Sizes

The B series of sizes follow the same idea as the A sizes. This means, each of the B series of paper size have an aspect ratio of 1 to the square root of 2.

So you get to the next size up by dividing the previous size exactly in half. For instance, cutting a B0 paper in half would give you two B1 size papers.

However, there is a small twist with the B series of paper sizes. The A series of papers come in the same dimensions all over the world.

But the B series can come in different dimensions depending on the region you are buying it from. Japan, for example, produces B series of paper with a different dimension.

In Japan, the B size of papers is around 6 percent larger in writing surface compared to the international standards.

The sizing of B series papers in Japan does not fall under the ISO code but rather their own, JTS codes which stand for the Japanese Industrial Standards Committee.

But there is another twist in this rule. The JTS B5 size of paper as per their other B series of paper is larger and has 3 percent more length and width.

But they also produce a size that they termed Size Semi B5 which matches the exact dimensions of the ISO B5 paper sizes.

Another thing that you need to remember with B size of paper is that they fall in between A series of papers. So, the size B3 sits right between A2 and A4 sizes.

The exact dimension of the ISO B0 series of paper is 100 cm by 141 cm or 39.4 inches by 55.7 inches.

### What Is B5 Paper?

B5 papers sit between A4 and A5 papers in terms of size. In the ISO code, the exact dimensions of B5 paper are 7 inches by 9.8 inches and the total area is 68.6 square inches. In Japan, however, the size is 7.2 inches by 10.1 inches.

## B5 Vs A4 Vs A5: Differences In Paper Sizes Explained

Now that you have a basic idea about the two series of papers and each of the three variants, it is time you looked at the differences between them with a looking glass.

Understanding it will help you decide whether you want to use B5, A4, and A5 sizes of paper for your next project. To that end, here are the key differences between the three sizes that you need to know about.

### 1. Size

The most obvious difference between the paper is their size. A4 papers have a total writing area of 96.7 square inches.

On the other hand, A5 papers have a much smaller area of only 48.2 square inches. B5 paper size compared to A4 is slightly smaller coming in at around 68.6 square inches. But it is still larger than A5 papers.

### 2. Region

The region that uses the papers also varies quite drastically. For instance, A4, A5, or A series of papers, in general, are a common sight in Europe, Asia, and Australian countries. But you will see them rarely used, if at all, in the United States.

However, B size of papers is more prevalent in regions of the Eastern side of Asia and the USA.

In Japan, the size of B series papers follows the JIS code which makes it a bit different from the standard ISO size of B series papers. They even have a semi B5 paper size which is the same as ISO B5 size.

### 3. Uses

To be fair though, the choice of paper size can vary from one person to another.

However, typically A4 and A5 series of papers are used more commonly for journals and notebooks, whereas B5 papers are mostly used for posters and invitations.

## How To Choose A Paper Size?

Different works and projects require different sizes of paper. So, understanding the different sizes and learning which size matches your needs is important if you want good productivity.

Here is a quick rundown of the best sizes for each different project that requires you to use paper.

### 1. For Journal

The journal is an oddly personal object to anyone who likes to write down their thoughts. It is a private item that lets you gather all your thoughts and feelings and look at them from a different perspective.

That is why it is quite hard to define the best size of paper for journal books.

However, most journal books on the market come in A5 or B6 sizes and that is considered quite standard by most people.

The B5 paper dimensions can also be perfect if you prefer a bit more area than A5 papers. However, that is a matter of personal preference more than anything else.

### 2. For Office Work

There are two things to consider when you are choosing a paper size for your office notebook, the size of your desk, and how much you might need to write.

If you have limited desk space, going with a smaller notebook is more practical as it eliminates clutter. But if you need to write a lot, this might not be the best idea.

We found that going with A4 or B5 paper sizes is the most practical choice for most office works. Some people even go with A5 sizes if they need a bit more space.

If you struggle to choose between A5 vs B5 paper, we recommend that you try out before you make your decision.

### 3. For School Notes

If you are a student and want to take notes in your notebook, you need to think about the size a bit more carefully. You need to find the right balance of writing surface and size.

However, since you will most likely be carrying it around on a backpack, it should not matter too much if the book is a bit larger.

The standard for most school notebooks or binders is A4 sizes. In the US, students almost exclusively write on letter size, which is the closes to A4 papers.

In some regions, students also use B5 or Semi B5 sizes which gives you a bit more writing area to work with.

### 4. For Pocket Notebook

Many people like to carry around a small notebook with them, whether to jot down some critical information on the fly or just to gather their thoughts from time to time.

With this type of notebook, you want them to be small enough so that you can carry them around with you in your pocket.

So naturally, these notebooks will have smaller papers compared to larger journals or school notebooks.

Typically, you can find pocket notebooks in three different sizes. A5, B6, and A6. If you want you can also go with a B5 size, however, the book will be a bit wider in that case.

### 5. For Sketchbook

With sketchbooks, you have complete freedom over your choice of paper sizes. You as an artist need to decide which size of paper would help you best visualize your creative thoughts and imagination.

If the B5 paper size is enough to doodle your thoughts, then by all means go for it.

To accommodate the needs of different artists, sketchbooks usually come in different sizes.

For larger drawing surfaces, you can even go with A2 or B2 size papers although they are a bit difficult to find. Typically, most artists draw on A4 to B5 size papers.

## Frequently Asked Questions (FAQs)

#### 1. What is the difference between US standard paper size and A4 standard size?

The standard paper size for most school or office works in the United States is letter size which has a dimension of 8.5 inches by 11 inches. An A4 paper on the other hand has a dimension of 8.3 inches by 11.7 inches.

So. as you can see the length and width of the two sizes are pretty close, but there is the slightest bit of differences between the two. The letter size used in the USA is slightly larger in length but also a bit small in terms of width.

#### 2. Why does Japan have different sizes of B series papers?

The main reason why Japan has different sizes of B series paper is that they use a different format than the ISO 216 format which is accepted as a standard in most countries. Their paper sizes are dictated by The Japanese Industrial Standards organization or JSA, for short.

In this sizing format, the B series papers have 1.5 times the size of the A series paper instead of the traditional square root of 2 system used by the ISO 216. That is why, even though it does not affect the size of the A series papers, it completely reinvents the sizing of B series papers.

#### 3. Which paper size is right for comics and illustrations?

Drawing comics and digital illustrations require a decent amount of space. That is why anything smaller than A4 size paper is not generally used for this sort of project. In the US comic artists typically use letter size papers which is almost similar to the ISO A4 size.

In Japan, there are many manga artists who frequently use the B series of paper. Keep in mind though, the JSA B sizes are typically a bit larger than the standard ISO ones. Even then, most comic and illustration artists use B4 papers for this type of work.

## Final Words

Understanding different paper sizes can feel complicated at first. But once you take some time to ruffle through the basic concepts, it becomes a lot easier. The core principle follows some mathematical logic that is quite easy to follow.

We hope our comprehensive article could help you learn the major differences between different paper sizes. So, you should have no trouble differentiating between A4 vs. B5 vs. A5 size of papers.