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Ten Things You Maybe Didn't Know About the Metre
1. It’s the foundation of the metric system
The metre (or meter, depending where you're from) is the core unit of length in the metric system. Everything else — millimetres, centimetres, kilometres — builds off of it.
2. It used to be based on the Earth
Originally, the metre was defined as one ten-millionth of the distance from the equator to the North Pole. Fancy, right? Not super practical, though, so we moved on.
3. Now it’s defined by the speed of light
Since 1983, a metre has been officially defined as the distance light travels in a vacuum in 1⁄299,792,458 of a second. That’s right — light speed is the new yardstick.
4. It’s spelled two ways
In most of the world, it’s “metre.” In the U.S., it’s “meter.” Same unit, different spelling — like colour vs. color. Metric users don’t get hung up on it.
5. It’s used literally everywhere
Science? Metres. Construction? Metres. Athletics? Metres. From architecture to engineering to track & field, the metre is the go-to unit almost everywhere outside the U.S.
6. It’s the Goldilocks of measuring units
Not too big, not too small — just right. The metre is great for measuring people, rooms, desks, or fences. It fits comfortably into most human-scale tasks.
7. The abbreviation is “m” — no uppercase
In SI units, “m” stands for metre, always lowercase. A capital “M” is for mega- (as in megawatt), so using the wrong case can really throw things off in science and tech.
8. It’s central in sports measurements
In track and field, swimming, and lots of Olympic events, everything is measured in metres. “100-metre sprint” is basically iconic at this point.
9. It replaced a lot of old units
Before the metric system, people used feet, cubits, rods, and all kinds of inconsistent local units. The metre came along and cleaned house with one standard rule.
10. It’s not going anywhere
The metre is embedded in global science, education, engineering, and trade. It’s precise, adaptable, and here to stay — even if a few countries still resist the metric wave.