Elevation Grade Calculator – Find Percentage or Length of Incline

Calculate the grade of an elevation in degrees or grade percentage and estimate the horizontal or vertical distance needed to support an incline to an elevation.


Grade, also referred to as slope, is the amount of incline of an elevation, for example the angle of the side of a hill. Grade can be expressed as the amount of rise over the amount of run, as a percentage, or as an angle measurement in degrees or radians.

Grade measurements are often used in projects ranging from roofing to road construction. See our roof pitch calculator to learn more about estimating the slope of a roof.

How to Find Grade of an Elevation

Grade can be found by measuring the horizontal length of an elevation, the run, and the vertical height of the elevation, the rise. Grade is expressed as rise/run, so if the rise is 25 and the run is 80 the grade is 25/80. This can be reduced to 5/16, use our reduce fractions calculator to help.

To find the percent of incline of a grade, solve the rise/run fraction as a decimal, then convert to a percentage. For example, if the grade is 5/16, solve as a decimal, which is .3125. To find the percentage multiply this decimal by 100, like this: 100 × .3125 = 31.25%.

The angle of incline can also be expressed in other units of angle measurement, such as radians or grads. Use our angle unit conversion calculators to convert your slope from degrees to another unit of measurement.