Calculate land slope from drop and length, or find missing drop, distance, angle, ratio, and per-foot grade in common units for drainage and ramps.

Use horizontal run, not distance along the sloping ground. Drop is a nonnegative magnitude. Presets are reference examples, not drainage or accessibility approval.

Optional settings

In percent inverse modes, choosing a preset fills slope. Actual requirements depend on the project.

Land Slope Formula

The following formula is used to calculate the Land Slope. 

LS = D / L × 100
  • Where LS is the Land Slope (%)
  • D is the total drop in the distance (ft) 
  • L is the horizontal run of the land (ft), not the sloping surface distance 

How to Calculate Land Slope?

The following example problems outline how to calculate Land Slope.

Example Problem #1:

  1. First, determine the total drop in distance (ft).
    • The total drop in distance (ft) is given as: 5.
  2. Next, determine the total length of the land (ft).
    • The total length of the land (ft) is provided as: 75.
  3. Finally, calculate the Land Slope using the equation above: 

LS = D / L * 100

The values given above are inserted into the equation below and the solution is calculated:

LS = 5 / 75 * 100 ≈ 6.67 (%)

FAQ

What is the significance of calculating land slope?
Calculating land slope is crucial for various engineering and construction projects. It helps in designing drainage systems, constructing roads and buildings, and in landscaping to ensure proper water runoff and prevent soil erosion. Understanding the slope of the land is also essential for agricultural practices to control irrigation and prevent waterlogging.

Can the land slope formula be used for any size of land?
Yes, the land slope formula (LS = D / L * 100) can be applied to any size of land, regardless of its dimensions. The key is to accurately measure the total drop in distance (D) and the horizontal run of the land (L) in the same units (e.g., feet or meters) before applying the formula. This universality makes it a valuable tool for various applications.

How can I measure the total drop in distance and the total length of the land accurately?
To measure the total drop in distance (D), you can use tools like a laser level or a surveyor’s transit to find the difference in elevation between the highest and lowest points of the land. For horizontal run (L), use the horizontal projection of the distance between the points. A tape, wheel or laser reading along the slope must be converted to horizontal distance before using this formula. It’s important to ensure that these measurements are as accurate as possible for a precise calculation of the land slope.