A4 vs Letter: What is the difference between A4 and US Letter size?
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A4 vs Letter: What is the difference between A4 and US Letter size?

Difference Between A4 And US Letter

The difference between A4 and letter size documents might not seem particularly important at first – until the time comes to print something out and choose the right dimensions. Knowing how to differentiate between A4 vs Letter size can make all the difference to print quality.

When you’re working in today’s globalized modern world, the chances are you’re going to be interacting with people from different parts of the world – using different paper sizes.

If a client from the US sends you a document, they’re likely to expect you to print it in US Letter size – the standard 8.5˝ by 11˝ paper measurement. The same is true for people in Canada. In the UK, and various other parts of the world, we use the A4 paper size, measuring 8.27” by 11.7”.

Here’s what you need to know about US Letter vs UK A4 sizing.

Letter vs A4 size: What’s the difference?

In most parts of the world, we follow the same general ideas on “standard” paper sizing. The ISO 216 series of paper sizing ensures no matter where you might be printing, you get the same results (more or less), due to the same paper dimensions.

Unfortunately, not everyone in the world follows by the same rules.

People in the US and North America are familiar with an entirely different set of paper sizes to people in the rest of the world. Due to the slightly different (wider) sizing, the same image or print-out would look different on a Letter document, than it would on A4.

The US Letter size, unlike the A4 and subsequent ISO 216 sizing guidelines, wasn’t designed with a unifying formula in mind. This sizing is designed exclusively by the American National Standards Institute (ANSI).

Let’s look at the differences between A4 and Letter paper:

A4 paperLetter Paper
Width x height (in mm):210 x 297 mm216 x 279 mm
Aspect ratio:1:1.41421:1.2941
Use:Almost every country.US, Canada, Mexico, Philippines, Chile, Venezuela, Columbia, and Bolivia.
Applications:Letters, forms, catalogs, magazines, laser printing, copying, and other documents.Official documentation.
History:Established by Dr Porstmann of Germany in 1920.Made standard for Federal forms by the Reagan administration.
Difference Between A4 And US Letter

A4 size vs Letter: What is A4 paper size?

A4 size is part of the comprehensive ISO 216 series of paper sizes, known as the “A series”. This formula for sizes was originally apparently discovered by physics professor George Lichtenberg in 1786 and was later used to create the ISO series.

Following the guidelines of the A-series formula, placing two pages of one size together to create a new sheet of paper will create the same aspect ratio. This makes it much easier to scale particular designs and images to different paper sizes and layouts.

If nothing else, the consistency of the A4 paper size, and the entire A Series, makes the paper simpler to work with for designers and creators. Because each page has the same aspect ratio, each item on the page retains its relative shape when sizing up or down.

Difference Between A4 And US Letter

Letter vs A4 size: What is US Letter size?

US Letter sizes are a little more complicated to work with because they don’t offer the same consistency. Just like the US is one of the only countries left which hasn’t made the switch from non-metric measurements, it’s also one of the few countries to avoid following the ISO standard.

There’s no derived starting point for US paper sizes, but Tabloid and Letter (two of the most popular options), are part of an old American National Standard Institute set of guidelines for technical drawing paper.

There aren’t any mathematical properties which make it easier to work with US Letter size when you’re creating graphical designs and print-outs either.

A lot of people assume one day the US Letter size will be phased out completely. This may become more likely as US companies continue to spread across borders to do more business with companies overseas.

As the world grows more globalized, we’ll need a more specific selection of standards for the way we manage and use paper.

UK A4 vs US Letter: Why does the difference matter?

You may be wondering why the difference between A4 vs US Letter paper matters if the measurements are only slightly changed. After all, it’s worth noting both of these page sizes are likely to look almost exactly the same at a glance.

It’s only upon further inspection you notice the A4 page is taller, and the US Letter is wider.

Problems begin to arise, unfortunately, when the time comes to print out various documents and magazines for companies – a common practice in the graphic design world.

You might create a file in the US which contains all of the graphical elements of a corporate magazine for a company in the UK. However, after sending the file to the customer for them to print out on their side of the pond, you would then potentially receive complaints the design doesn’t “look right”.

This is because UK printers are likely to be set automatically to A4 paper size, which would mean every file would be adjusted to fit this new page size. Printers are only semi-intelligent, so they adjust their printing mechanisms based on the page sizes they think they have in their trays.

There are even some printers which will altogether refuse to print documents which aren’t set to the expected paper format, without any explanation as to why the print isn’t working. This leaves your customers bewildered and confused when they’re trying to access their content.

Difference Between A4 And US Letter

Addressing the problem of A4 vs Letter size

Probably the best way to solve the problems associated with different “page” sizes around the world, is to avoid sending documents which depend on external factors to display and print correctly.

This means you wouldn’t send anything in a “Word” document because Microsoft Word can automatically adjust the margins on a document when someone opens on a file.

Finding the right format to send your content in will likely be one of the most important factors in ensuring the success of your project. Any program which would encode and translate the files into a slightly different set of sizes would immediately cause problems

Acrobat files are often the best option, because the file format won’t automatically change from one computer to another. However, it’s best to make sure you know exactly what kind of programs your clients or partners are working with before you start sending different file types.

If your client doesn’t have access to Acrobat content, they might attempt to convert your files into a different document type, which creates the conversion and size problems all over again.

Mastering the A4 vs Letter conundrum

As designers and companies continue to work together from different points around the globe, it’s becoming increasingly important to “standardize” certain aspects of how we collaborate.

For many designers and graphic artists, this will include making sure to outline expectations regarding paper sizes and printing processes before files are issued.

Using a document processor or file type which also allows you to send your file without any alterations to the sizing of certain margins will also be extremely valuable.

In an ideal world, we’ll eventually get to a point where every company can use the same sizing for their printing and paper. However, until the US and a handful of other countries decide to join the ISO standard, graphic designers are going to need to figure out a workaround.

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William Baker
Digital producer
William Baker
Digital producer
As our digital producer, Will regularly contributes to the pages of Brand Fabrik, our online publication dedicated to branding, marketing and design. Will enjoys relaying his enthusiasm for technology and its impact on the creative services sector. He also relishes the opportunity to review the latest design-related products and gadgets.

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