Aydın Tiryaki (2026)

For centuries, humanity attempted to conduct trade and science using subjective measures like a handspan, a foot, or a dram. However, the Industrial Revolution and the rise of global trade made a common “language of measurement” an absolute necessity. Today, the world has largely navigated the famous crossroads between the Metric System (SI), the symbol of rationality, and the Imperial System, the fortress of tradition.

1. Europe: The Rational Legacy of the Revolution

France is the cradle of the metric system. The “equality” principle of the 1789 French Revolution manifested itself not only in law but also in measurements. As Napoleon’s armies traversed Europe, they carried with them not just muskets, but also the “meter” and the “kilogram.” Today, the European continent is a geography where the metric system, the language of science and commerce, is used in its purest form without compromise.

2. Turkey: A Radical Leap into Modernization

Turkey has executed one of the most successful and rapid unit transformations in the world. The chaos of “okka, arşın, and endaze” from the Ottoman era was replaced by the metric system with the Measurement Law adopted in 1931. This change was not merely a technical preference; it was a concrete step of the young Republic’s will to integrate with the world and reach the level of contemporary civilizations. Today, Turkey is a country where the metric system dominates everything from daily life to high technology.

3. The Soviet Union and the Eastern Bloc: The Power of Standardization

In 1918, the Soviet Union discarded the complex units of Tsarist Russia and mandated the metric system. The strict state standards known as GOST linked everything from nuclear reactors to simple screw threads through the metric system. This discipline persists today as a steadfast technical heritage across the former Soviet geography, including Central Asia, the Caucasus, and Eastern Europe.

4. The Far East: The Dance of Tradition and Modernity

China and Japan built their modernization processes on the foundation of the metric system.

• Japan: Reconstructed its industry entirely on metric grounds after World War II.
• China: While the metric system is the official standard, they married tradition with modernity by fixing the “Jin” (a traditional weight unit) to exactly 500 grams.In these countries, while engineering is 100% metric, the scents of the past still linger in local marketplaces.

5. The Arab World and the Gulf States

In Arab countries, the situation was shaped by colonial history. North Africa (the Maghreb), under French influence, is entirely metric, whereas the situation is more complex in the British-influenced Gulf countries (Saudi Arabia, UAE). Particularly in the oil and gas sector, due to US influence, units like “barrel, feet, and PSI” are still standard, while daily life and transportation follow a purely metric and kilometric order.

6. The “Persistent” Duo: USA and UK

While the rest of the world has “metricated,” the USA and the UK still cling to the “inch, mile, and pound” systems of the past.

• The United Kingdom: Exists in a state of limbo. Road signs are in miles and beer is served in pints, yet supermarket weights are metric and fuel is sold by the liter.
• The USA: One of the only three countries in the world (along with Liberia and Myanmar) that has not officially adopted the metric system. However, a “hidden metric system” prevails in critical sectors like science, medicine, and aerospace. This resistance creates billions of dollars in “unit conversion costs” for global trade every year.

[Image comparing US Gallons vs UK Gallons and Pints]

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Global Status Summary (2026)

Region	Dominant System	Status
Europe / Russia / Turkey	Metric (SI)	Absolute and Precise Dominance
Asia / South America	Metric (SI)	Official Standard, Local Traditions Exist
United Kingdom	Hybrid	Tradition in Social Life, Metric in Industry
United States	Imperial (USC)	Official Resistance, Mandatory Metric in Tech

Conclusion: The Metric System as a Global Language

Today, officially, almost all of the 195 countries in the world have accepted the metric system. In the world of science, medicine, and international trade, everything outside the metric system is now considered a “local dialect.” From an engineering perspective, the rationality of the decimal system is not just a convenience; it is the only bridge that minimizes error and ensures universal communication.

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A Note on Methods and Tools: All observations, ideas, and solution proposals in this study are the author’s own. AI was utilized as an information source for researching and compiling relevant topics strictly based on the author’s inquiries, requests, and directions; additionally, it provided writing assistance during the drafting process. (The research-based compilation and English writing process of this text were supported by AI as a specialized assistant.)