Definition
Kilometre
A kilometre is a metric unit of length equal to exactly 1000 metres.
What it means
Kilometres suit long distances such as routes between places. To change kilometres to metres, count 1000 metres for each kilometre.
Remember it
One kilometre is a chain of 1000 metres.
Example
One lap is 750 m. Four laps cover 4 × 750 m = 3000 m = 3 km.
Watch for
A kilometre measures distance, not speed; speed needs a time unit too, such as km/h.
Common mix-up
km is kilometre; kg is kilogram.
Exact meaning
The symbol km names a kilometre. Its length is exactly 1000 metres.