Which is correct, 10 km or 10 kms?

The Kilometer Conundrum: Why it’s Always “km,” Never “kms”

We’ve all seen it, perhaps even used it ourselves: “kms” instead of “km” when referring to multiple kilometers. But is adding that “s” a simple case of pluralization? The answer, surprisingly, is a resounding no.

The key lies in understanding the fundamental nature of metric units and their accompanying symbols. The metric system, a meticulously designed framework for measurement, utilizes specific symbols, not abbreviations. This distinction is crucial. Abbreviations are shortened versions of words, often ending with a period (though not always). Symbols, on the other hand, are standardized representations that remain constant, regardless of context or quantity.

Think of it like a scientific formula. We don’t change the “H” in H2O just because there are two hydrogen atoms. Similarly, “km” is the designated symbol for kilometer. Whether you’re talking about a short 1 km run or the epic 2,306 km journey from Winnipeg to Vancouver, the symbol remains consistently “km.”

Adding an “s” to “km” to indicate plurality is simply incorrect within the established conventions of the metric system. “kms” has no recognized meaning in this context. It’s a common misconception, likely stemming from our ingrained habit of pluralizing nouns. However, sticking to the correct “km” maintains clarity, consistency, and adherence to the internationally recognized standards of the metric system.

So, the next time you’re describing distances, remember the rule: “km” is your go-to symbol, whether you’re referring to one kilometer or a thousand. Embrace the elegant simplicity of the metric system, and ditch the “s” – your writing (and scientific accuracy) will thank you for it.