Navigation & Maps
Contour Interval
The difference in height between neighbouring contour lines on a map, for example 10 or 20 metres.
In the wild
"If the contour interval is 20 metres, moving from one contour line to the next represents a 20-metre change in elevation."
Why it matters
Always check the interval: the same number of lines can mean very different climbs on different maps.
Rex's tip: Check the interval in the map legend before you count lines.