Metre (Meter) — Definition, Formula & Examples
A metre (spelled "meter" in American English) is the basic unit of length in the metric system. It is about the distance from a doorknob to the floor, or roughly one large step for an adult.
The metre is the SI (International System of Units) base unit of length, defined as exactly 100 centimetres or 1,000 millimetres. One metre equals approximately 3.281 feet or 1.094 yards.
How It Works
You use metres to measure medium-sized lengths like the height of a room, the length of a car, or the distance across a playground. For smaller objects, you switch to centimetres (cm) or millimetres (mm). For longer distances, you use kilometres (km). To convert between these units, remember that each step up multiplies by a power of 10: 1 m = 100 cm, 1 m = 1,000 mm, and 1 km = 1,000 m.
Worked Example
Problem: A classroom is 8 metres long. How many centimetres is that?
Recall the conversion: There are 100 centimetres in 1 metre.
Multiply: Multiply the number of metres by 100.
Answer: The classroom is 800 centimetres long.
Why It Matters
Nearly every country in the world uses metres as the standard unit for everyday length measurements. Science classes, sports (track events are measured in metres), and construction all rely on the metric system, so understanding the metre is essential from an early age.
Common Mistakes
Mistake: Confusing metres with centimetres when measuring, leading to answers that are 100 times too large or too small.
Correction: Always check your unit. A door is about 2 metres tall, not 2 centimetres. If your answer seems unreasonably big or tiny, you may have used the wrong unit.