## Slope

Slope in percent (%)

In many countries road gradientes are signed as a percentage. The steepest road in the world is Baldwin Street in Dunedin, New Zealand with a with a 35% grade.

Slope in per millee (‰)

Some railways specify the steepness in per mille.

Angle in °

The geometric angle is being represented in grade. Valid values are from -90 to +90. An angle in 90° represents an infinite (∞) slope.

Ratio (1:x)

Railways in many countries still specify the slope as a ratio. The flat slope is being specified as 1:∞.

For more information you could go to http://en.wikipedia.org/wiki/Grade_(slope)