A History of Paper Sizes: How the World Couldn’t Agree on Something as Simple as a Sheet of paper

It’s remarkable, really, that in a world capable of sending rovers to Mars and the editing of genes, we’ve never quite managed to agree on what size a piece of paper should be. The humble sheet is divided by borders more stubborn than any political or geographic boundary. 

The story begins, like many international standards, with Europe quietly tidying its drawers while America did its own thing. The now-ubiquitous A-series paper sizes (A0, A1, A2, and so on) come from Germany’s early 20th-century attempt to bring order to the chaos of stationery. In 1922, the German Institute for Standardization (DIN) introduced DIN 476, defining paper by one simple mathematical principle: every size in the A-series has an aspect ratio of 1:√2 (roughly 1:1.414). 

This, frankly, is genius. This ratio means that when you fold an A0 sheet in half along its long edge, you get two A1 sheets, and so on down to A4, the office favourite. No wasted paper, no odd proportions, just neat scalability. It’s the origami of rational bureaucracy. 

The idea spread across Europe and, eventually, most of the world, becoming ISO 216.  

The United Kingdom officially adopted it in 1975, when the German system officially became ISO 216 (or 1959, following UK adoption after WWII, depending on who you ask, and having flirted with various “foolscap” sizes before then), and today, it’s the international norm, except, perhaps inevitably, in North America. 

Enter the Americans (and their Letters) 

Across the Atlantic, the United States had already developed its own standard, if one can use that word without irony. The Letter size (8½ × 11 inches, or roughly 216 × 279 mm) became the default for American printers and typewriters, though no one seems to know why. 

The most credible origin story involves early paper mills cutting large sheets into quarters to make them easier to handle, resulting in dimensions that were simply convenient rather than geometric. Bureaucratic inertia then did the rest. Once millions of filing cabinets, folders, and trays were built around 8½ × 11 inches, changing the system became unthinkable. 

Thus, while Europe’s A4 is elegantly proportioned and mathematically consistent, the U.S. Letter is a little shorter and wider; a sort of stockier cousin. 

A quick guide to the A-series 

For the numerically minded, here’s the scale of the A-series in brief: 

Each step up halves the surface area, while maintaining that magical 1 : √2 ratio. The whole system is an ode to Germanic precision. The sort of thing one imagines was drafted on graph paper with great satisfaction. 

The curious case of B and C 

Of course, there are also B and C series papers, which sound like budget airlines but are actually companion sizes. 

B-series fills the gaps between A sizes, providing dimensions that are the geometric mean between two consecutive A sizes. Useful for posters and books. C-series, meanwhile, exists for envelopes: a C4 envelope neatly fits an A4 sheet, a C5 fits an A5, and so on. A small mercy in a world of correspondence. 

Why the difference matters 

At first glance, the Letter/A4 divide seems trivial. A few millimetres here or there. But in practice, it creates a low-level international nuisance. Printing and formatting, where an A4 document opened on an American printer can clip margins or reflow text. Stationery imports, where files, folders, and binders don’t quite match up. Design layouts, resulting in page templates, business cards, and publication specs differing subtly but infuriatingly. 

The European A-series appeals to reason; the U.S. Letter to tradition. It’s a philosophical divide in paper form. Rationalism versus practicality. Or perhaps, more simply, the difference between what happens in a design meeting and a workshop. 

Other remnants and oddities 

Before A4 conquered British desks, the land was littered with quaintly named paper sizes: Foolscap folio (8 × 13 inches) was common for legal documents, and Quarto or Octavo for books. These relics survive mainly in dusty archives and crossword clues. 

In Japan, meanwhile, ISO 216 coexists with traditional “JIS” sizes, including B-series papers that are slightly larger than the European equivalents. And the U.S. itself isn’t monolithic. It also uses Legal (8½ × 14 in) and Tabloid (11 × 17 in) formats, mostly for contracts and newspapers. In other words; we’ve invented endless ways to write the same thing on slightly different sized rectangles. 

Does it still matter today? 

You might think, in an age of PDFs and digital screens, that paper dimensions no longer matter. Yet, paper sizes remain embedded in software, printers, and even digital design templates. “A4” or “Letter” isn’t just a physical size. It’s a setting that shapes layouts, margins, and export defaults. 

Furthermore, standards are cultural shorthand. They reveal how societies approach order. ISO 216 represents a belief in universality, in shared systems that make life neater and more predictable. The U.S. Letter, by contrast, embodies a certain independence. The charming refusal to metricate that makes some sigh into their tea. 

Practicalities 

If you work internationally: 

• Always check the default paper size in Word or your printer settings. It might switch between A4 and Letter unannounced. 

• When sending documents abroad, export as PDF to preserve formatting. 

• For design or print work, specify exact dimensions in millimetres or inches rather than just “A4” or “Letter.” 

And if you’re ever tempted to merge the two systems in a shared office, don’t. It leads to jammed printers, passive-aggressive Post-it notes, and a great deal of exasperation. 

In conclusion 

Paper sizes, like tea strengths or socket shapes, prove that global harmony is always one conversation away from falling apart. Europe’s system is elegant, America’s is entrenched, and neither is likely to budge. 

Still, for a world that occasionally tears itself apart over bigger matters, perhaps the enduring A4/Letter divide is reassuring: a reminder that even our disagreements can be reassuringly regular.