Elevation Grade Calculator: Measure Slope Angle & Steepness

Welcome to our elevation grade and slope calculator.

The elevation grade between two points, also known as the steepness or slope, is a measurement that has many different uses, particularly in construction, architecture, engineering, and landscaping.1To Determine Percent of Slope and Angle of Slope | U.S. Geological Survey. (n.d.). Www.usgs.gov. https://www.usgs.gov/educational-resources/determine-percent-slope-and-angle-slope

It is also useful for runners or athletes who want to calculate the steepness of a particular incline or vertical change.

This calculator can be used to calculate the elevation grade of a slope based on horizontal distance (run) and vertical distance (rise), providing you with the elevation grade as a decimal, a percentage, and a ratio, in addition to the angle of elevation.

These values are calculated using basic trigonometry.

The distances can be entered in either metric or imperial (US) units, whereby you can choose from mm, cm, inches, feet, yards, meters, kilometers, and miles.

Elevation Grade Calculator

Elevation Grade Calculator



What Is Elevation Grade?

Elevation grade is a measure of the steepness of a slope.

The elevation grade is equivalent to the run (horizontal length) divided by the rise (vertical length).

rise/run triangle explanatory diagram

Slope Diagram: The Relationship Between Angle Of Elevation & Elevation Grade Visualized

As outlined in the diagram below, an elevation grade of 1 equates to an angle of elevation of 45 degrees. An elevation grade of 1 is also equivalent to a percentage grade of 100%.

An elevation grade of more than one equates to an angle of elevation of more than 45 degrees.

An elevation grade of less than one equates to less than a 45-degree angle of elevation.

Elevation Grade Calculator: Measure Slope Angle & Steepness 1

Slope Ratio Explained

Slope ratio refers to the ratio between the rise and the run.

For example, a slope ratio of 1:5 means every 5 units travelled horizontally, 1 unit is travelled vertically.

How To Use The Elevation Grade Calculator

How To Measure Horizontal Distance (Run) and Vertical Distance (Rise)

To determine the elevation grade, you need to know the rise/run.

At the most basic level, these can be calculated using a tape measure or another manual measuring device.

On a larger and more precise level, a surveyor’s transit and a leveling rod can be used.

Alternatively, a clinometer can also be used.

In construction or other professional settings, high-tech and high-accuracy surveying equipment will almost always be used when measuring elevation grade.

What To Do Once You Know The Rise/Run

Once you know the rise and run, whatever units they may be measured in, simply enter them into the calculator and click the ‘Calculate’ button to get your result.

How Does The Elevation Grade Calculator Work?

Firstly, the calculator converts the distances to the same unit of measurement.

Then, to calculate the grade in decimals, the vertical distance is divided by the horizontal run.

The grade percentage is calculated by multiplying this value by 100.

The angle of elevation is calculated by multiplying the grade in decimals by 180/π.


How Steep Is A 20 Percent Grade?

To help understand the steepness of percentage grade numbers, they can be converted to ratios.

For example, a 20% elevation grade is equivalent to a ratio of 1:5. This means that for every 5 units traveled horizontally, there is a 1 unit vertical decrease or increase.

A 5% elevation grade is equivalent to a 1:20 ratio, meaning 20 units have to be traveled horizontally for a 1 unit change in height.

How To Use An Elevation Grade Calculator For A Hiking Trail

If you know the elevation change from one point of a trail to the next, as well as the distance between these two points, then you can calculate the average elevation grade between these two points.

However, bear in mind that a trail is unlikely to have a uniform elevation gain or decrease for the duration of the trail. Part of the trail may have a steep grade, and part may have a relatively flat grade.

Therefore, rather than calculating the average grade of the entire trail at once, it may be worth breaking the trail into shorter segments and calculating the elevation grades of individual sections.2Calculating “Typical” Grade of a Hiking Trail. (2023, April 26). Physics Forums: Science Discussion, Homework Help, Articles. https://www.physicsforums.com/threads/calculating-typical-grade-of-a-hiking-trail.1051974/

What Road Has The Steepest Elevation Grade In The World?

Baldwin Street in Dunedin, New Zealand, is recognised by the Guinness World Records as the steepest road in the world, with a whopping gradient of 34.8%.

It briefly lost the title from 2017 to 2020 to Ffordd Pen Llech in Harlech, Wales. However, it’s title was reinstated after it was determined that the steepness of the street has to be measured along its central axis, passing the medal back to Baldwin Street.3Guinness World Records. (2020, April 8). Baldwin Street in New Zealand reinstated as the world’s steepest street. Guinness World Records. https://www.guinnessworldrecords.com/news/2020/4/baldwin-street-in-new-zealand-reinstated-as-the-worlds-steepest-street-614287

The reason why Baldwin Street is so steep is that the city was planned from abroad by town planners in London who knew nothing of the topography of the area. It was not intentionally designed to be so steep.

What Is The Optimal Gradient For A Railroad?

A 1 in 80 gradient (1.25%) is usually the maximum allowed, however, some exceptions, for example, the Channel Tunnel between England and France, may reach a gradient of up to 1:40.4Standards Catalogue. (n.d.). Www.rssb.co.uk. https://www.rssb.co.uk/standards-catalogue

How Do I Use An Elevation Grade Calculator To Determine The Slope For A Wheelchair Ramp?

To correctly calculate the measurements for a wheelchair ramp, you’re best off using a specific wheelchair ramp calculator from one of the following links:

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