Contour Line Elevation Gain Calculator

Contour Line Elevation Gain Calculator

Before GPS devices made elevation tracking automatic, hikers and mountaineers estimated total elevation gain on a route by counting how many contour lines the trail crossed on a topographic map.

Elevation Gain = Contour Lines Crossed x Contour Interval

Example

Crossing 25 contour lines on a map with a 40-foot contour interval:

Elevation Gain = 25 x 40 = 1,000 ft (304.8 m)

Contour Interval Varies by Map

The contour interval - the elevation difference between adjacent lines - is printed in the map's legend and varies significantly by map scale and terrain type, typically ranging from as little as 10 feet on detailed local trail maps up to 100 feet or more on larger-scale regional maps covering more rugged terrain. Always check the specific map's legend rather than assuming a standard interval, since using the wrong interval value would proportionally throw off this entire calculation.

Still Useful Today

Even with modern GPS elevation tracking widely available, understanding contour line reading remains a fundamental backcountry navigation skill - useful for route planning ahead of time, cross-checking GPS device readings, and continuing to navigate confidently if electronic devices fail in the field.