There are two common standard paper sizes for sheets and printing paper: US Letter-size and A4. Although they are both standard sizes, they are not used in every country and that is why we are sometimes overwhelmed when we want to buy refill paper or notebooks, especially online, since we don’t get to touch the products.
US letter-size paper is widely used in North America. However, the standard paper size in most other countries is A4.
You have probably already wondered what paper size you should buy or if it makes a significant difference either to get one size or the other.
Short video illustrating the size difference between the ISO A4 and the US Letter sizes.
On the one hand, when we just look at the measurements, both sizes seem quite similar. On the other hand, if we compare both sizes by overlapping them, just like we can see on the video, we can easily see that A4 is slightly narrower and longer than Letter-size, which means that if you have to print a document that was designed in a different size you are likely to end up with a distorted image.
Consequently, it is safe to say that size is not important for many things, but it does matter when we are talking about printable products.
Since these two common paper sizes have variants that are also frequently used for printed notebooks, digital notebooks, planners and journals, we are going to take a closer look at each of them.
Here is an overview of what you can read in the coming sections:
ISO A standard paper sizes
The ISO A standard paper sizes consist of a logical set of sheet sizes that are defined by the ISO 216 standard. The ISO 216 is a standard for office paper. It was created by the International Organization for Standardization (ISO). The ISO develops standards for all its 165 countries, including the US, in a variety of fields. The aim is to standardize as much as possible, but when it comes to paper sizes, the ISO 216 is still not used by all ISO member states.
The ISO A series in pictures
A4 size is part of a series of paper sizes specified in the ISO 216. Let us take a closer look at the A-series. We will start with A0 and then we are going to work our way down to the smaller sizes, which are commonly used on printing paper, digital notebooks and digital planners.
An A0 sheet is a big format. Its area equals one square meter. All dimensions are specified in inches as well as in centimetres.
If you cut an A0 in half you will get two A1 sheets. Two A1 sheets side by side are the same size of an A0 sheet.
Cutting an A1 in half you will get two A2 sheets. Two A2 sheets side by side are the same size of an A1 sheet.
Half of an A2 is an A3 sheet. Two A3 sheets side by side are the same size of an A2 sheet.
To get the next size down, just cut an A3 in half and it will give two A4 sheets. Two A4 sheets side by side are the same size of an A3 sheet.
Cut an A4 in half and you get two A5 sheets. Two A5 sheets side by side are the same size of an A4 sheet.
If you halve an A5, you get two A6 sheets. Two A6 sheets side by side are the same size of an A5 sheet.
And if you cut an A6 in half, you will get two A7 sheets. Two A7 sheets side by side are the same size of an A6 sheet.
This could continue, until you run out of paper to fold. In other words, if you want a smaller size, you just need to keep halving.
We can also reverse the process by starting with one of the smaller sizes and then working our way up to bigger sizes. It’s very easy to understand. If you want a bigger size, you keep on doubling your sheets. This means that if you pair up two sheets of any size within the A series, you will get the next size up.
The ISO A series chart
In the size chart below, you can see the most commonly used standard paper sizes within the ISO A series.
Size chart illustrating the ISO A series
In short, ISO A paper scale is based on a meter. By halving a page, you can get the next standard size down and by doubling the page you will get the next standard size up. The smaller the number, the bigger the page.
ISO paper sizes in portrait view
|A series|| Width|
ISO A series best feature: constant height/width ratio
Also relevant is aspect ratio: height/width ratio remains constant for all sizes. Due to the A-scale aspect ratio, it is able to keep the same proportions each time it is cut in half. In other words, when you are enlarging or reducing something that you have created on A-sized documents, you can easily scale your projects up or down perfectly. Since every different sheet size is in the same ratio, you will not get a distorted effect. That is probably one of the reasons why it was so widely adopted all over the word.
Although the ISO A series is the most frequently used page scale, ISO also includes other standard sizes, such as ISO B sizes, which can be used for poster printing for example and ISO C, which are commonly used for envelopes.
American standard paper sizes
Most of the countries that didn’t adopt ISO 216 standard, use North American paper sizes such as Letter, Legal and other sizes included in the ANSI series.
Just like A4 size sheets, Letter-size is also part of a set or range of page sizes, namely the ANSI standard. ANSI stands for American National Standards Institute.
Letter-size, also known as ANSI A or American Quarto, is the closest to the A4 size. It is therefore not a coincidence that they are commonly used on the same type of home or office stationery products.
The related paper size known as half letter, statement, or organizer L is exactly one half of the US Letter size: 8.5 by 5.5 inches (215.9 by 139.7 mm).
A Legal sized document has the same width as a Letter sized document but is 14 inches high.
The ANSI standard paper sizes
The ANSI standard was created to establish a set of sizes that are based on shared dimensions. However, it doesn’t have the consistent aspect ratio of the ISO A-series.
ANSI standard paper sizes in centimetres and inches
Letter (ANSI A)
Ledger (ANSI B)
Tabloid (ANSI B)
If you are thinking of buying refill paper online you should play it safe. Take your time before you click the ‘buy now’ button. I suggest you always check the dimensions of the products you buy online, especially if you are buying loose leaf paper for a notebook or a planner that you have purchased previously.
If you are creating digital resources to sell online, I suggest you stick to the standard formats and, whenever possible, create multiple versions of the same product, so that your clients can choose the one that best suits them. This will for sure force you to spend more time while you are designing your product lines, but in the long run it will eventually pay off. Instead of printing a different size and getting a distorted image, your clients will get a perfect print of the product you have designed and hopefully return to your shop later.