Uphill

Uphill describes a surface or direction that moves upward. It is used as an adjective and adverb to designate an incline or slope that rises relative to a reference level. The opposite direction is downhill, describing a surface or route that descends.

In geography and engineering, slope steepness is expressed as a grade (percent) or an angle (degrees). Grade = rise over run × 100. A 10% grade rises 10 meters for every 100 meters forward; an angle of about 5.7 degrees corresponds to roughly a 10% grade. Road design and cycling commonly categorize grades from gentle to moderate to steep, with the steepest sections often found on mountain routes, ski runs, or long urban climbs. Uphill motion requires work against gravity, and energy expenditure increases with elevation gain, varying with speed, weight, and terrain.

Metaphorically, uphill is used to describe tasks or journeys that are difficult or progress that is slow and challenging, as in “an uphill battle” or “an uphill climb.”

Geographically, uphill can describe any slope that rises relative to its surroundings, including hills, ramps, sidewalks, and hiking or cycling trails, not limited to natural terrain.

See also downhill, gradient, incline, slope.